List of all sections and keywords¶

selection type: [string]

Keyword to give the type of atom selection. Required keyword.

Valid keyword values are:

• list A list of atoms will be given

• range A range of atoms will be given

• central atom A central atom and a radius will be given

[method string]: [list, range or radius]

Keyword to give the list, range or radius for an active space treated at the given level of theory.

Valid method strings:

• hf

• ccs

• cc2

• ccsd

• cc3

• ccsd(t)

A list is specified using set notation: {1,2,3}.

A range is specified as [1,3] (equivalent to {1,2,3}).

A radius is specified by a double precision real (e.g. 1.0d2) and is always in Angstrom units. The atoms within the radius \(r\) of the central atom then define the active atoms.

Example: First three atoms in the input are chosen as HF active atoms space.

- active atoms
   selection type: list
   hf: {1,2,3}

central atom: [integer]

Specifies the central atom in the active space. Requested for selection type: central atom.

inactive basis: [string]

Specifies the basis set on the inactive atoms, that is the atoms not specified in the active atoms section. Optional.

Valid keyword values are basis sets available in \(e^T\).

[method string] basis: [string]

Set basis for active space treated at a given level of theory. Optional.

Valid method strings:

• hf

• ccs

• cc2

• ccsd

• cc3

• ccsd(t)

Valid keyword values are basis sets available in \(e^T\).

Example: First three atoms in the input are chosen as CCSD active atoms space with aug-cc-pVDZ basis.

- active atoms
   selection type: range
   ccsd: [1,3]
   ccsd basis: aug-cc-pVDZ

canonical: {[real], [real]}

The first number specifies the amount of active electrons and the second number the amount of active molecular orbitals. The orbitals are selected by energy starting from the orbital with lowest energy.

freeze atom cores: {[int], ...}

Default: false

Enables the frozen core approximation, where the core orbital of selected atoms are frozen. The atoms are specified by integers referring to the number of the atom in the geometry section.

freeze core: {[int], ...}

Default: false

Enables the frozen core approximation. Selected MOs can be frozen by specifying the MO indices in a list. If no list is given the core MOs of all atoms will be frozen. Optional.

localized

Default: false

This enables the construction of localized Hartree-Fock orbitals after SCF is converged. Optional.

interaction type: [string]

Default: photon

Specifies the type of the boson-matter interaction. Currently photon and plasmon are supported.

modes: [integer]

Specifies the number of boson modes.

frequency: {[real], ...}

Specifies the boson frequency/energy (\(\omega\)) in atomic units. Number of parameters given must be equal to the number of modes.

boson states: {[integer], ...}

Default: 1

Specifies the number of boson states per boson mode. Number of integers given must be equal to the number of modes.

coupling: {[real], ...}

Default: 0.0

Specifies the light-matter coupling \(\lambda= \sqrt{4\pi/V_{\text{eff}}}\) in atomic units. Required in photon calculations. Number of parameters given must be equal to the number of modes.

polarization: {[real],[real],[real]}

Specifies the transversal polarization vector (\(\vec{\epsilon}\)). Only used in photon calculations.

wavevector: {[real],[real],[real]}

Specifies the direction of the wavevector (\(\vec{k}\)). Only used in photon calculations.

coupling bilinear: {[real], ...}

Overwrites the bilinear light-matter coupling \(\lambda \sqrt{\omega/2}\). Number of parameters given must be equal to the number of modes.

coupling self: {[real], ...}

Overwrites the light-matter self-coupling \(0.5 \lambda^2\). Number of couplings given must be equal to the number of modes.

coherent state: {[real], ...}

Specifies the coherent state / displacement for each boson mode. Number of parameters given must be equal to the number of modes.

boson number: {[int], ...}

Maximum number of boson occupations to be used in the strong coupling calculations for each mode.

quadrupole oei

Assume complete basis (\(\sum_p |p\rangle\langle p| = 1\)) to rewrite the self-interaction with quadrupole moments, removing references to the virtual density. Only used in photon calculations.

cbo: {[real], ...}

Specifies the displacement q of the field for each boson mode. Number of parameters given must be equal to the number of modes.

print dipole eri construction

Prints the transformation of the two electron integral in the basis that diagonalizes the dipole operator.

Bath orbital

Default: false

Add a bath orbital to the calculation with zero orbital energy and zero electron repulsion integrals.

dipole

Calculation of coupled cluster ground state dipole moment.

quadrupole

Calculation of coupled cluster ground state quadrupole moment.

molecular gradient

Calculation of the coupled cluster ground state molecular gradient, if implemented. The gradient is printed to a separate output file.

propagation

Default: false

Perform real-time propagation of the coupled-cluster state.

fft dipole moment

Default: false

Perform complex fast Fourier transform of the dipole moment time series from an earlier real-time propagation calculation.

fft electric field

Default: false

Perform complex fast Fourier transform of the electric field time series from an earlier real-time propagation calculation.

polarizabilities: {[character], [character], ...}

Enables the calculation of polarizabilities, and gives the option to specify cartesian componens (xx`, yz, etc.). Specifying components is optional.

transition moments

Enables the calculation of transition moments.

eom

Properties will be calculated within the equation of motion formalism.

Either this or the lr keyword must be specified.

Available for CCS, CC2, CCSD, and CC3.

lr

Properties will be calculated within the linear response formalism.

Either this or the eom keyword must be specified.

Available for CCS, CC2, and CCSD.

dipole length

Compute transition dipole moments in length gauge.

dipole velocity

Compute transition dipole moments in length, velocity and mixed gauge.

rotatory strength

Compute rotatory strength in length and velocity gauge.

frequencies: {[real], [real], ...}

Frequencies, in Hartree, for which the polarizability shall be computed. Required for polarizabilities.

asymmetric

Enables the calculation of polarizabilities based on an asymmetric expression. This allows the user to avoid calculating the response of one of the two components for the polarizability. Instead both amplitude and multiplier response must be calculated for the desired component.

Asymmetric polarizabilities are only available for eom and require the response components keyword to be set.

response components: {[character], [character], ...}

The components for which to calculate amplitude and multiplier response for asymmetric polarizabilities.

initial states: {[real], [real], ...}

Default: {0} (Only the ground state is considered.)

Numbers of the states for which the transition/permanent moments shall be computed.

permanent moments

Enables the calculation of permanent moments.

dyson orbitals

Enables the calculation of Dyson orbitals.

full-space transition moments

Enables the calculation of full-space transition moments after band Lanczos calculations. This comes in addition to the reduced-space initial-final state transition moments calculated in the band Lanczos solver.

damping: [real]

Default: 0 (No damping.)

Damping to be used in the damped response solver.

dipole

Calculation of the CI ground state dipole moment.

quadrupole

Calculation of the CI ground state quadrupole moment.

dipole

Calculation of the CI transition dipole moment.

quadrupole

Calculation of the CI transition quadrupole moment.

initial states: {[real], [real], ...}

Default: {0} (Only the ground state is considered.)

Numbers of the states from which the CI transition/permanent moments shall be computed.

final states: {[real], [real], ...}

Default: {0} (Only the ground state is considered.)

Numbers of the states to which the CI transition/permanent moments shall be computed.

functional: [string]

Specifies the DFT XC functional as defined in LibXC: https://www.tddft.org/programs/libxc/functionals/

Some common functionals can be defined by:

• lda : lda_x + lda_c_vwn_rpa

• lsda : lda_x + lda_c_vwn_rpa

• pbe : gga_x_pbe + gga_c_pbe

• blyp : gga_x_b88 + gga_c_lyp

• pbe0 : hyb_gga_xc_pbeh

• b3lyp : hyb_gga_xc_b3lyp

• bhandhlyp : hyb_gga_xc_bhandhlyp

• sogga11x : hyb_gga_x_sogga11_x + gga_c_sogga11_x

exchange: [string]

Specifies the DFT Exchange functional as defined in LibXC: https://www.tddft.org/programs/libxc/functionals/

correlation: [string]

Specifies the DFT Correlation functional as defined in LibXC: https://www.tddft.org/programs/libxc/functionals/

hf percentage: [real]

Specifies the HF Exchange percentage for Hybrid DFT Functionals

cholesky eri

Keyword to run a Cholesky decomposition of the two-electron integrals. Note that this is done automatically for any coupled cluster calculation, the keyword should only be given if only Cholesky decomposition is to be performed.

ground state

Keyword to run a ground state calculation at the level of theory given in the method section. Enables the ground state or reference engine.

geometry optimization

Keyword to run a geometry optimization. Enables the geometry optimization engine. Only ground state optimizations are available for HF, while excited state optimized structures are also available at the CC level of theory. Depending on the availability, the optimization will be performed with analytical gradients (available for HF and CCSD) or numerical gradients (if analytical is not available).

harmonic frequencies

Keyword to determine vibrational frequencies and normal modes for HF and CC methods. Recommended to use for methods that have analytical gradients (HF and CCSD). A default calculation determines the frequencies and the normal modes. See harmonic frequencies section for additional calculations (such as Wigner sampling).

mean value

Keyword to calculate coupled cluster expectation values. Enables the mean value engine, which determines the coupled cluster ground state amplitudes and multipliers, and calculates the requested expectation value. Which mean value(s) to calculate are specified in the cc mean value section.

excited state

Keyword to run a coupled cluster excited state calculation. Enables the excited state engine, which calculates the ground and excited state amplitudes.

response

Keyword to enable the coupled cluster response engine. Implemented features are EOM transition moments and polarizabilities for CCS, CC2, CCSD and CC3, and LR transition moments and polarizabilities for CCS. The response engine drives the calculation of ground state amplitudes and multipliers, excited state vectors (left and right eigenvectors of the Jacobian matrix) and the requested property.

restart

Global restart keyword to activate restart where possible.

real time

Keyword to run coupled cluster time propagation. Enables the time-dependent engine.

shielding

Keyword to run CPHF nuclear shielding tensors.

tdhf excited state

Keyword to run TDHF excitation energies (Tamm-Dancoff or RPA).

tdhf response

Keyword to run TDHF response calculation (polarizabilities).

envelope: {[integer], [integer],...}

Envelope of electric field pulse \(1,2,\ldots\).

Valid keyword values are:

• 1 Use Gaussian envelope.

• 2 Use sine squared envelope.

x polarization: {[real], [real], ...}

\(x\) polarization component of electric field pulse \(1,2,\ldots\).

y polarization: {[real], [real], ...}

\(y\) polarization component of electric field pulse \(1,2,\ldots\).

z polarization: {[real], [real], ...}

\(z\) polarization component of electric field pulse \(1,2,\ldots\).

central time: {[real], [real], ...}

Central time of the envelope of electric field pulse \(1,2,\ldots\).

width: {[real], [real], ...}

Temporal width of the envelope of electric field pulse \(1,2,\ldots\) in atomic units. The width corresponds to the Gaussian root-mean-squared width of a pulse with a Gaussian envelope and the period of a pulse with a sine squared envelope.

carrier angular frequency: {[real], [real], ...}

Angular frequency of the carrier wave of electric field pulse \(1,2,\ldots\) in atomic units.

peak strength: {[real], [real], ...}

Amplitude of the carrier wave of electric field pulse \(1,2,\ldots\) in atomic units.

phase shift: {[real], [real], ...}

Carrier-envelope phase shift of electric field pulse \(1,2,\ldots\). The shift corresponds to the difference between the maxima of the envelope and the carrier wave.

repetition: {[real], [real], ...}

Default: {1, 1, ...} (a single instance of each pulse)

Number of instances of electric field pulse \(1,2,\ldots\).

separation: {[real], [real], ...}

The temporal separation between repetitions of electric field pulse \(1,2,\ldots\).

maximum angular order: [int]

Default: 30

Maximum angular order of Lebedev quadrature

minimum angular order: [int]

Default: 15

Minimum angular order of Lebedev quadrature

partitioning: [string]

Default: Becke partitioning

Partitioning applied to the the atoms.

quadrature: [string]

Default: Gauss-Chebyshev

Radial quadrature. Possible values:

• Gauss-Chebyshev

• Treutler-Ahlrics

radial threshold: [real]

Default: 1.0E-6

Threshold of the radial quadrature. Lower values increase the quality (and numbers of points) of the grid.

cube side: [real]

If present, build a grid using the specified quantity as side of the discretization cubes (for debug porpuses only)

cube offset: [real]

If present, offset applied to the minimum/maximum atomic cartesian coordinates along each direction to construct the grid (for debug porpuses only)

gradient displacement: [real]

Default: \(10^{-3}\) (or 1.0d-3)

Displacement for numerical differentiation used to evaluate gradients which are used to evaluate the Hessian.

gradient method: [string]

Default: analytical

Specifies whether to evaluate gradients using analytical calculation or numerical.

Valid keyword values are:

• analytical Analytical gradient evaluation.

• central difference Numerical differentiation with central differences (recommended for numerical differentiation).

• forward difference Numerical differentiation with forward differences.

hessian displacement: [real]

Default: \(10^{-4}\) (or 1.0d-4)

Displacement for numerical differentiation used to evaluate Hessian. Method used is central differences based on either analytical or numerical gradients.

run geometry optimization

If specified, the geometry will first be optimized before the frequency calculation. Otherwise the frequency calculation will be performed at the input geometry.

state: [integer]

Default: \(0\)

Specifies the state to calculate the Hessian for. State = 0 corresponds to the ground state, state = 1 to the first excited state, and so on.

wigner samples: [integer]

Perform 0 K Wigner sampling. This will produce the number of samples specified, sampled from a normal mode Wigner distribution at T = 0 K. The created samples are stored as wigner_sample_0.dat, wigner_sample_1.dat, and so on, where each .dat file contains first the sampled geometry and then the sampled momentum (FMS90 format).

wigner seed: [integer]

Default: \(0\)

Seed used in random number generator for the Wigner sampling. If not specified, eT will use the default seed (obtained from wigner seed: 0). The seed will produce reproducable Wigner samples for a given integer type (either 32 or 64).

dipole

Calculation of the HF dipole moment.

quadrupole

Calculation of the HF quadrupole moment.

molecular gradient

Calculation of the HF molecular gradient, if implemented. The gradient is printed to a separate output file.

cholesky storage: [string]

Default: memory if they take up less than 20% of the total memory; disk otherwise

Specify how to store the Cholesky vectors. Optional.

Valid options are:

• memory Store Cholesky vectors in memory.

• disk Store Cholesky vectors on file.

eri storage: [string]

Default: memory if the entire matrix is needed in the calculation and they take up less than 20% of the total memory; none otherwise

Specify how to store the electron repulsion integrals. Optional.

Valid options are:

• memory Store full electron repulsion matrix in memory.

• none Always construct the integrals from Cholesky vectors.

mo eri in memory

Default: false

Override defaults and store full MO ERI matrix in memory if true. Recommended for time-dependent CC.

t1 eri in memory

Default: false

Override defaults and store full T1 ERI matrix in memory if true.

ri: [string]

Default: None

Enables the RI approximation for the integrals and provides the auxiliary basis set.

Valid options are any available auxiliary basis set.

biorthogonalize last: [integer]

Default: The maximum number of iterations given by the singlet states keyword.

The number of last generated Lanczos vectors that the band Lanczos algorithm should orthogonalize the vector generated at the current iteration against.

chain length: [integer]

Specifies the dimension of the reduced (Krylov sub-) space for the asymmetric Lanczos algorithm. Required for algorithm: asymmetric lanczos.

deflation threshold: [real]

Default: \(10^{-12}\) (or 1.0d-12)

Minimum value of the norm of the right or left Lanczos vector generated at any iteration. The right or left band Lanczos space is deflated if the norm goes below this threshold.

lanczos normalization: [integer]

Default: asymmetric

Specifies the type of biorthonormalization for the asymmetric Lanczos algorithm. Optional.

Valid keyword values are:

• asymmetric Which enables \(\tilde{p} = p\) and \(\tilde{q} = \frac{q}{p\cdot q}\)

• symmetric Which enables \(\tilde{p} = \frac{p}{\sqrt{|p\cdot q|}}\) and \(\tilde{q} = \text{sgn}(p\cdot q)\frac{q}{\sqrt{|p\cdot q|}}\)

max energy: [real]

Default: 1000

Maximum energy of the states checked for convergence and/or stored in the band Lanczos algorithm, in Hartree.

min energy: [real]

Default: -1000

Minimum energy of the states checked for convergence and/or stored in the band Lanczos algorithm, in Hartree.

min transition strength: [real]

Default: 0.0

Minimum transition strength of the states checked for convergence and/or stored in the band Lanczos algorithm, to any of the initial states specified with the restart states keyword, in Hartree.

operators: {integer, integer, ... }

List of operators used for starting vectors based on operators and initial states. Each number in the list corresponds to a number at the same position in the restart states list. The integer 0 specifies the unit operator, and cannot be given together with the number 0 in the restart states list (cannot use the ground state as a starting vector). The numbers 1, 2 and 3 give the X, Y and Z dipole operators, respectively. The numbers 4, 5, 6, 7, 8 and 9 give the XX, XY, XZ, YY, YZ and ZZ quadrupole operators, respectively.

overlap threshold: [real]

Default: \(10^{-14}\) (or 1.0d-14)

Specifies the minimum value of the dot product of the right and left Lanczos vector generated at an iteration. The algorithm breaks down, and the iteration loop is exited, if the overlap goes below this threshold.

restart states: { integer, integer, ... }

Default: List of integers from 1 to the integer specified with the singlet states keyword.

List of precomputed initial states used for restart and operator starting vectors. Each number in the list corresponds to a number at the same position in the operators list. The integer 0 specifies the ground state, and must be given together with a number greater than 0 in the operators list (cannot use the ground state as a starting vector). An integer greater than 0 specifies the precomputed excited state with the given number, and can be used together with all operator numbers. If the excited state does not exist on file, a default start vector will be used instead.

skip convergence

Skips testing the convergence of the states calculated using the band Lanczos algorithm, implying that all the calculated states are stored on file.

available: [integer]

Default: 8

Specifies the available memory, default units are gigabytes. Optional.

unit: [string]

Default: GB

Specifies the units for the specified available memory. Optional.

Valid keyword values are:

• B

• KB

• MB

• GB

levels: [string], [string], ...

Specifies the level of theory for the different active spaces. Required keyword.

Valid keyword values are:

• ccs

• cc2

• ccsd

cc2 orbitals: [string]

Specifies the type of orbitals used for orbital partitioning in MLCC2. Required keyword.

Valid keyword values are:

• cnto-approx Approximated correlated natural transition orbitals

• cholesky Cholesky orbitals (occupied and virtual)

• cholesky-pao Cholesky occupied orbitals and projected atomic orbitals for the virtuals.

• nto-canonical Natural transition orbitals for occupied and canonical for virtuals.

ccsd orbitals: [string]

Specifies the type of orbitals used for orbital partitioning in MLCCSD. Required keyword.

Valid keyword values are:

• cnto-approx Approximated correlated natural transition orbitals

• cholesky Cholesky orbitals (occupied and virtual)

• cholesky-pao Cholesky occupied orbitals and projected atomic orbitals for the virtuals.

• nto-canonical Natural transition orbitals for occupied and canonical for virtuals.

cholesky threshold: [real]

Default: \(1.0\cdot 10^{-2}\) (or 1.0d-2)

Threshold for the Cholesky decomposition of the density. Only used with cc2 orbitals: cholesky or cc2 orbitals: cholesky-pao

cnto occupied cc2: [integer]

Determines the number of occupied orbitals in the CC2 orbital space for the MLCC2 calculation.

cnto virtual cc2: [integer]

Default: \(n_v^{\text{CC2}} = n_o^{\text{CC2}}\cdot\frac{n_v}{n_o}\)

Sets the number of virtual orbitals in the CC2 orbital space for the MLCC2 calculation. Optional.

cnto occupied ccsd: [integer]

Determines the number of occupied orbitals in the CCSD orbital space for the MLCCSD calculation.

cnto virtual ccsd: [integer]

Default: \(n_v^{\text{CCSD}} = n_o^{\text{CCSD}}\cdot\frac{n_v}{n_o}\)

Sets the number of virtual orbitals in the CCSD orbital space for the MLCCSD calculation. Optional.

cnto states: {[integer], [integer], ...}

Determines which CCS excited states are used to construct the approximated CNTOs.

print ccs calculation

Default: false

Enables the printing of the CCS calculation in the case of cc2 orbitals: cnto-approx or ccsd orbitals: cnto-approx. Optional.

print cc2 calculation

Default: false

Enables the printing of the CC2 calculation in the case of ccsd orbitals: cnto. Optional.

nto occupied cc2: [integer]

Determines the number of occupied orbitals in the CC2 orbital space for the MLCC2 calculation.

nto occupied ccsd: [integer]

Determines the number of occupied orbitals in the CCSD orbital space for the MLCCSD calculation.

canonical virtual cc2: [integer]

Default: \(n_v^{\text{CC2}} = n_o^{\text{CC2}}\cdot\frac{n_v}{n_o}\)

Sets the number of virtual orbitals in the CC2 orbital space for the MLCC2 calculation. Optional.

canonical virtual ccsd: [integer]

Default: \(n_v^{\text{CCSD}} = n_o^{\text{CCSD}}\cdot\frac{n_v}{n_o}\)

Sets the number of virtual orbitals in the CCSD orbital space for the MLCCSD calculation. Optional.

nto states: {[integer], [integer], ...}

Determines which CCS excited states are used to construct the NTOs.

cnto restart

Default: false

If specified, the solver will attempt to restart from previously determined CNTO matrices (M and N). Optional.

nto restart

Default: false

If specified, eT will attempt to restart from previously determined NTO matrices (M and N). Optional.

orbital restart

Default: false

If specified, orbital partitioning is skipped and MLCC orbitals (and sizes of orbital sets) are read from file. Optional.

forcefield: [string]

Default: non-polarizable

Specifies the forcefield to be used for the MM portion.

Valid keyword values are:

• non-polarizable Electrostatic QM/MM Embedding

  Note

  The charge has to be provided for each atom in the geometry section.

• fq Fluctuating Charge force field.

  Note

  The electronegativity and chemical hardness has to be provided for each atom in the geometry section.

algorithm: [string]

Default: mat_inversion

Selects the algorithm to be used to solve the FQ equation. So far only the inversion algorithm is implemented. Optional.

initial hf optimization

Default: false

Enables an initial optimization of the full density through a standard HF calculation to a low threshold.

initial hf threshold: [real]

Default: \(1.0\cdot10^{-1}\) (or 1.0d-1)

Threshold for the initial HF optimization. Should only be specified if initial hf optimization is also specified.

print initial hf

Default: false

Enables the printing of the initial HF optimization in the case that initial hf optimization is given. Optional.

cholesky virtuals

Default: false

Enable the use of Cholesky decomposition of the virtual AO density to construct the active virtual orbitals. The default is to use projected atomic orbitals.

cholesky threshold: [real]

Default: \(1.0\cdot10^{-2}\) or (1.0d-2)

Threshold for the Cholesky decomposition of the AO density to construct an active space.

project on minimal basis

Default: false

First diagonalization of the AO fock matrix will be performed in a minimal basis.

no mo screening

Default: false

Disables screening based on the MO-coefficients in MLHF.

type: [string]

Default: None

Determines the type of functional to use for orbital localization.

Valid keyword values are:

• edmiston-ruedenberg

• foster-boys

orbitals: [string]

Default: None

Determines which orbital sets to localize. Either occupied, virtual, or both. In the latter case, the orbitals are localized separately to obtain new Hartree-Fock orbitals (i.e., there is no occupied-virtual mixing).

Valid keyword values are:

• occupied

• virtual

• both

threshold: [real]

Default: \(10^{-6}\) (or 1.0d-6)

Threshold below which the maximum element of the gradient needs to be to stop the orbital localization procedure. Optional.

input: [string]

Specifies if the input parameters are given in the \(e^{T}\) input file or in an external file handled directly by the external library PCMSolver. Required.

Valid keyword values are

• external

  Note

  No further input has to be given to pcm because the parameters have to be specified in an external .pcm-file.

• internal

solvent: [string]

Specifies the solvent outside the cavity.

Valid keyword values

tesserae area: [real]

Default: 0.3

Area of the finite elements (tesserae) the surface is constructed from given in square Angstrom.

solver type: [string]

Default: iefpcm

Selects the type of solver to be used to solve the PCM equation.

Valid keyword values are

• iefpcm Integral Equation Formalism PCM

• cpcm conductor-like PCM

output print level: [string]

Specifies the print level for the main output file. Default is normal. Optional.

Valid keyword values are:

• minimal Only banners, final results like total energies or excitation energies, solver settings, and other essential information.

• normal In addition to minimal, print iteration information, amplitude analysis, and other non-essential information.

• verbose In addition to normal, print all relevant information for users. This can make the output difficult to read and navigate.

• debug In addition to verbose, prints information mostly relevant for debugging code that behaves unexpectedly.

timing print level: [string]

Specifies the print level for the timing file. Default is normal. Optional.

Valid keyword values are:

• minimal Total solver timings, total program time, and other essential timings.

• normal In addition to minimal, iteration times and details like time to calculate omega, the Fock matrix, and other expensive terms.

• verbose In addition to normal, times for subtasks, such as micro-iteration times as well as individual contributions to the omega vector.

• debug In addition to verbose, prints timings mostly relevant for debugging code that behaves unexpectedly.

full references

If specified, implementation references will be printed in APA style. Otherwise, only the DOIs are printed to the output file.

z-matrix

If specified, prints the z-matrix to the output file.

singlet states: [integer]

Specifies the number of singlet excited states to calculate.

triplet states: [integer]

Specifies the number of triplet excited states to calculate.

algorithm: [string]

Default: davidson for CCS, CC2, MLCC2, and CCSD; non-linear davidson for lowmem-CC2 and CC3.

Solver to use for converging the excited state equations.

Valid keyword values are:

• davidson

  Use Davidson algorithm with residuals preconditioned with the orbital differences approximation of the Jacobian. Cannot be used for lowmem-CC2 and CC3.

• diis

  Use DIIS algorithm with update estimates obtained from the orbital differences approximation of the Jacobian. Can be used for lowmem-CC2 and CC3.

• non-linear davidson

  Use the non-linear Davidson algorithm with residuals preconditioned with the orbital differences approximation of the Jacobian. Can be used for lowmem-CC2 and CC3.

• asymmetric lanczos

  Use the asymmetric Lanczos algorithm for excitation energies. EOM oscillator strengths will be calculated as well. Cannot be used for lowmem-CC2, MLCC2, and CC3.

• asymmetric band lanczos

  Use the asymmetric band Lanczos algorithm for excitation energies and EOM-CC transition/oscillator strengths. Cannot be used for lowmem-CC2, MLCC2, and CC3.

right eigenvectors

Default: true

If specified, solve for the right eigenvectors of the Jacobian matrix. This keyword should only be specified for an excited state calculation. For property calculations, the program will solve for both left and right vectors. Optional.

left eigenvectors

Default: false

If specified, solve for the left eigenvectors of the Jacobian matrix. This keyword should only be specified for an excited state calculation. For property calculations, the program will solve for both left and right vectors. Optional.

energy threshold: [real]

Default: \(10^{-3}\) (or 1.0d-3)

Energy convergence threshold, as measured with respect to the previous iteration. Optional.

residual threshold: [real]

Default: \(10^{-3}\) (or 1.0d-3)

Threshold of the \(L^{2}\)-norm of the residual vector of the excited state equation. Optional

core excitation: { integer, integer, ... }

Default: false

Solve for core excitations within the CVS approximation. The integers specify which orbitals to excite out of. Orbitals are ordered according to orbital energy (canonical orbitals). If the keyword has been specified, CVS will be activated automatically. Optional.

remove core: { integer, integer, ... }

Default: false

Valence excitations, but with excitations from core MOs projected out. The integers specify which core orbitals from which one should not excite. Orbitals are ordered according to orbital energy (canonical orbitals). Optional.

ionization

Default: false

Solve for ionized state. If this keyword is specified, the ionized state will be calculated using a bath orbital and projection similar to CVS. Optional.

max iterations: [integer]

Default: 100

The maximum number of iterations. The solver stops if the number of iterations exceeds this number. Optional.

diis dimension: [integer]

Default: 20

Number of previous DIIS records to keep. Optional.

restart

Default: false

If specified, the solver will attempt to restart from a previous calculation. Optional.

storage: [string]

Default: disk

Selects storage of excited state records. Optional.

Valid keyword values are:

• memory Stores records in memory.

• disk Stores records on file.

crop

Default: false

If specified, the CROP version of DIIS will be enabled. Optional.

max reduced dimension: [integer]

Default: \(\max(100, 10 n_\mathrm{s})\), where \(n_\mathrm{s}\) is the number of singlet states specified by singlet states: [integer] in the solver cc es section.

The maximal dimension of the reduced space of the Davidson procedure. Optional.

max micro iterations: [integer]

Default: \(100\)

Maximum number of iterations in the non-linear Davidson solver. Optional.

rel micro threshold: [real]

Default: \(10^{-1}\) (or 1.0d-1)

Threshold for convergence in the micro iterations of the non-linear Davidson solver. This threshold is relative to the current norm of the residuals.

state guesses: {i=integer, a=integer}, {i=integer, a=integer}

Specifies start guesses for excited states in terms of transitions from occupied orbital \(i\) to virtual \(a\). Optional.

olsen

Enable the Olsen update in Davidson. Will use a more accurate preconditioner which may improve convergence. Optional.

algorithm: [string]

Default: newton-raphson for CC3, diis for other coupled cluster methods

Solver to use for converging the amplitude equations. Optional.

Valid keyword values are:

• diis Quasi-Newton algorithm accelerated by DIIS. Uses the orbital differences approximation of the coupled cluster Jacobian.

• newton-raphson. Newton algorithm accelerated by DIIS.

energy threshold: [real]

Default: \(10^{-5}\) (or 1.0d-5)

Energy convergence threshold, as measured with respect to the previous iteration. Optional.

residual threshold: [real]

Default: \(10^{-5}\) (or 1.0d-5)

Threshold of the \(L^{2}\)-norm of the amplitude equations vector \(\Omega_\mu = \langle \mu \vert \bar{H} \vert \text{HF} \rangle\). Optional.

multimodel newton: [string]

Default: on for CC3, off for other coupled cluster methods

If specified as on, the Newton-Raphson algorithm will solve the micro-iterations using a lower-level approximation of the Jacobian matrix. Must be combined with algorithm: newton-raphson. Optional.

crop

Default: false

If specified, the CROP version of DIIS will be enabled. Optional.

max iterations: [integer]

Default: 100

The maximum number of iterations. The solver stops if the number of iterations exceeds this number. Optional.

max micro iterations: [integer]

Default: 100

The maximum number of micro-iterations in the exact Newton solver (see algorithm: newton-raphson). The solver stops if the number of iterations exceeds this number. Optional.

rel micro threshold: [real]

Default: \(10^{-2}\) (or 1.0d-2)

The relative threshold \(\tau\) used for micro-iterations by the exact Newton solver (see algorithm: newton-raphson). The micro-iterations are considered converged if the \(L^{2}\)-norm of the Newton equation is less than \(\tau \vert\vert \boldsymbol{\Omega} \vert\vert\). Optional.

storage: [string]

Default: disk

Selects storage of DIIS records in coupled cluster calculations. Optional.

Valid keyword values are:

• memory Stores DIIS records in memory.

• disk Stores DIIS records on file.

micro iteration storage: [string]

Default: value of the keyword storage

Selects storage of records in the micro iterations (if any) in ground state coupled cluster calculations. Optional.

Valid keyword values are:

• memory Stores records in memory.

• disk Stores records on file.

diis dimension: [integer]

Default: 8

Number of previous DIIS records to keep. Optional.

restart

Default: false

If specified, the solver will attempt to restart from a previous calculation. Optional.

algorithm: [string]

Default: diis for ccs, lowmem-cc2, and cc2; newton-raphson for cc3; davidson for other coupled cluster models.

Solver to use for converging the multiplier equation. Not supported for MLCC2.

Valid keyword values are:

• davidson Use Davidson algorithm with residuals preconditioned with orbital differences approximation of the Jacobian. Cannot currently be used for lowmem-CC2, CC2, and CC3.

• diis Use DIIS algorithm with update estimates obtained from the orbital differences approximation of the Jacobian.

• newton-raphson. Newton algorithm accelerated by DIIS.

threshold: [real]

Default: \(10^{-5}\) (or 1.0d-5)

Threshold of the \(L^{2}\)-norm of the residual vector of the multiplier equation. Optional.

max iterations: [integer]

Default: 100

The maximum number of iterations. The solver stops if the number of iterations exceeds this number. Optional.

diis dimension: [integer]

Default: 20

Number of previous DIIS records to keep. Optional.

restart

Default: false

If specified, the solver will attempt to restart from a previous calculation. Optional.

storage: [string]

Default: disk

Selects storage of solver subspace records. Optional.

Valid keyword values are:

• memory Stores records in memory.

• disk Stores records on file.

crop

Default: false

If specified, the CROP version of DIIS will be enabled. Optional.

max reduced dimension: [integer]

Default: 100

The maximal dimension of the reduced space of the Davidson procedure. Optional.

max micro iterations: [integer]

Default: 100

The maximum number of micro-iterations in the exact Newton solver (see algorithm: newton-raphson). The solver stops if the number of iterations exceeds this number. Optional.

micro iteration storage: [string]

Default: disk

Selects storage of records in the micro iterations (if any). Optional.

Valid keyword values are:

• memory Stores records in memory.

• disk Stores records on file.

rel micro threshold: [real]

Default: \(10^{-2}\) (or 1.0d-2)

The relative threshold \(\tau\) used for micro-iterations by the exact Newton solver (see algorithm: newton-raphson). The micro-iterations are considered converged if the \(L^{2}\)-norm of the Newton equation is less than \(\tau\). Optional.

multimodel newton: [string]

Default: on for CC3, off for other coupled cluster methods

If specified as on, the Newton-Raphson algorithm will solve the micro-iterations using a lower-level approximation of the Jacobian matrix. Must be combined with algorithm: newton-raphson. Optional.

integrator: [string]

Specifies the integration method used for real-time propagation. Required.

Valid keyword values are:

• rk4 Fourth-order Runge-Kutta (RK4)

• gl2 Second-order Gauss-Legendre (GL2)

• gl4 Fourth-order Gauss-Legendre (GL4)

• gl6 Sixth-order Gauss-Legendre (GL6)

• dopri5 Dormand-Prince 5(4) (DOPRI5)

• dop853 Dormand-Prince 8(5,3) (DOP853)

initial time: [real]

The start time for the real-time propagation given in atomic units. Required.

final time: [real]

The end time for the real-time propagation given in atomic units. Required.

time step: [real]

Size of the time steps for the real-time propagation given in atomic units. Required.

method: [string]

Default: tdcc

Specifies the real-time coupled cluster method used for real-time propagation. Optional.

Valid keyword values are:

• tdcc Time-dependent coupled cluster method.

• elementary td-eom-cc Elementary basis time-dependent equation-of-motion coupled cluster method.

• diagonal td-eom-cc Diagonal basis time-dependent equation-of-motion coupled cluster method.

steps between output: [integer]

Default: \(1\)

Specifies how many time steps the solver should take between each time output (energy, dipole moment, …) is written to file. Optional.

implicit threshold: [real]

Default: \(10^{-11}\) (or 1.0d-11)

Specifies how tightly the Euclidian norm of the residual of implicit Runge-Kutta methods should converge before going to the next time step. Optional.

energy output

Default: false

Write energy to file every steps between output. Optional.

dipole moment output

Default: false

Write dipole moment to file every steps between output. Optional.

electric field output

Default: false

Write electric field to file every steps between output. Optional.

parameters output

Default: false

Write time-dependent parameters to file every steps between output. The parameters are the cluster amplitudes and Lagrange multipliers for TDCC, and the EOM-CC right and left amplitudes for TD-EOM-CC. Optional.

mo density matrix output

Default: false

Write molecular orbital (MO) density matrix to file every steps between output. Optional.

max error: [real]

Default: 1.0e-10

Maximum value of error estimate of embedded methods. Time step size is halved if estimate is greater than this value. Optional.

min error: [real]

Default: 1.0e-12

Minimum value of error estimate of embedded methods. Time step size is doubled if estimate is smaller than this value. Optional.

step reduction factor: [int]

Default: 2

Factor by which the propagation solver divides and multiplies the time step size in embedded methods, in order to keep the error estimate between the values of max error and min error. Optional.

threshold: [real]

Default: \(10^{-3}\) (or 1.0d-3)

Residual norm threshold for convergence. Optional.

gradient response threshold: [real]

Default: \(10^{-5}\) (or 1.0d-5)

Residual norm threshold for convergence of amplitude response equations needed when computing CCSD level excited state gradients. Optional.

storage: [string]

Default: disk

Storage for Davidson records. Optional.

Valid options are:

• disk Store records on file.

• memory Store records in memory.

max iterations: [real]

Default: \(100\)

The maximum number of iterations. The solver stops if the number of iterations exceeds this number. Optional.

threshold: [real]

Default: \(10^{-4}\) (or 1.0d-4).

Decomposition threshold. All electron repulsion integrals will be reproduced by the Cholesky vectors to within this threshold. This threshold puts an upper limit to the accuracy of coupled cluster calculations. Optional.

batches: [integer]

Default: 1

Number of batches \(n_b\) in partitioned Cholesky decomposition. In this procedure, the Cholesky basis is chosen from a reduced set generated by decomposing diagonal blocks of the matrix (of which there are \(n_b\)). Introduces an error of about an order of magnitude higher than threshold. Optional.

one center

Default: false

If specified, the Cholesky decomposition is restricted to diagonal elements \(g_{\alpha\beta,\alpha\beta}\) for which both atomic orbital indices, \(\alpha\) and \(\beta\) , are centered on the same atom. Introduces an error of about \(10^{-3}\) that cannot be reduced further by threshold. Optional.

span: [real]

Default: \(10^{-2}\) (or 1.0d-2)

Span factor \(\sigma\) . For a given iteration of the Cholesky decomposition, this number determines the range of possible pivots to select/qualify: \(D_{\alpha\beta} \geq \sigma D_\mathrm{max}\) . Optional.

qualified: [integer]

Default: \(1000\)

Maximum number of qualified pivots in an iteration of the Cholesky decomposition. Optional.

mo screening

Perform Cholesky decomposition such that the MO electron repulsion integrals are targeted. The default screening targets the AO integrals.

energy threshold: [real]

Default: \(10^{-6}\) (or 1.0d-6)

Energy convergence threshold, as measured with respect to the previous iteration. Optional.

residual threshold: [real]

Default: \(10^{-6}\) (or 1.0d-6)

Threshold of the \(L^{2}\)-norm of the residual vector of the CI equation. Optional

max reduced dimension: [integer]

Default: 100

The maximal dimension of the reduced space of the Davidson procedure. Optional.

max iterations: [integer]

Default: 100

The maximum number of iterations. The solver stops if the number of iterations exceeds this number. Optional.

start guess: [string]

Default: single determinant

Specifies start guesses for CI. Optional.

Valid keyword values are:

• single determinant Set a single element of the CI vector to one for every state. For the ground state it corresponds to the HF determinant.

• random Gives random starting guess to the coefficient of the CI vector.

states: [integer]

Default: 1

Specifies the number of states to calculate. Optional.

restart

Default: false

If specified, the solver will attempt to restart from a previous calculation. Optional.

storage: [string]

Default: disk

Selects storage of records for the CI vectors. Optional.

Valid keyword values are:

• memory Stores records in memory.

• disk Stores records on file.

max iterations: [integer]

Default: 100

The maximum number of iterations. The solver stops if the number of iterations exceeds this number. Optional.

max reduced dimension: [integer]

Default: 50

The maximal dimension of the reduced space of the Davidson procedure. Optional.

residual threshold: [real]

Default: \(10^{-3}\) (or 1.0d-3)

Threshold of the \(L^{2}\)-norm of the residual vector of the response equation. Optional.

restart

Default: false

If specified, the solver will attempt to restart from a previous calculation. Optional.

storage: [string]

Default: disk

Selects storage of solver subspace records. Optional.

Valid keyword values are:

• memory Stores records in memory.

• disk Stores records on file.

max iterations: [integer]

Default: 100

The maximum number of iterations. The solver stops if the number of iterations exceeds this number. Optional.

max reduced dimension: [integer]

Default: 200

The maximal dimension of the reduced space of the CPP procedure. Optional

residual minimization

Specifies that residual minimization should be used to solve the reduced space equations in the damped response solver. This procedure might in some cases improve convergence. Optional.

residual threshold: [real]

Default: \(10^{-11}\) (or 1.0d-11)

Threshold of the \(L^{2}\)-norm of the residual vector of the excited state equation. Optional.

restart

Default: false

If specified, the solver will attempt to restart from a previous calculation. Optional.

storage: [string]

Default: disk

Selects storage of excited state records. Optional.

Valid keyword values are:

• memory Stores records in memory.

• disk Stores records on file.

initial time: [real]

Specifies the start of the interval of interest in the time series file to Fourier transform. Required.

final time: [real]

Specifies the end of the interval of interest in the time series file to Fourier transform. Required.

time step: [real]

Specifies the time step between the data points in the time series file to Fourier transform. Required.

padding initial time: [real]

Specifies the initial time that the time series will be padded from. Solver will use the value of the time series at initial time for every time step between padding initial time and initial time. Optional.

hann window

Modulates the time series (including potential padding) with a Hann function. Optional.

rectangular window

Modulates the time series (including potential padding) with a rectangular function. This is the default. Optional.

state: [integer]

Default: 0

Selects state to perform geometry optimization on. Optional. State: 0 corresponds to the ground state, 1 to the first excited state, and so on.

algorithm: [string]

Default: bfgs

Selects the solver to use. Optional.

Valid keyword values are:

• bfgs A Broyden-Fletcher-Goldberg-Shanno (BFGS) solver using redundant internal coordinates and a rational function (RF) level shift obtained from an augmented Hessian.

max step: [real]

Default: \(0.5\) (or 0.5d0)

Maximum accepted step length in \(L^{2}\)-norm. Rescales the step to the boundary otherwise. Optional.

energy threshold: [real]

Default: \(10^{-6}\) (or 1.0d-6)

Energy convergence threshold, as measured with respect to the previous iteration. Optional.

residual threshold: [real]

Default: \(3\times 10^{-4}\) (or 3.0d-4)

Threshold checking the absolute maximal value of the energy gradient with respect to the previous iteration. Optional.

residual rms threshold: [real]

Default: \(1.2*10^{-4}\) (or 1.2d-4)

Threshold checking the root mean square of the energy gradient with respect to the previous iteration. Optional.

displacement threshold: [real]

Default: \(1.2\times 10^{-4}\) (or 1.2d-4)

Threshold checking the maximal value of the absolute displacements of the atoms with respect to the previous iteration. Optional.

displacement rms threshold: [real]

Default: \(1.2*10^{-4}\) (or 1.2d-4)

Threshold checking the root mean square of the displacements of the atoms with respect to the previous iteration. Optional.

max iterations: [integer]

Default: 100

The maximum number of iterations. The solver stops if the number of iterations exceeds this number. Optional.

restart

Default: false

If specified, the solver will attempt to restart from a previous calculation. Optional.

gradient method: [string]

Default: analytical

Selects the gradient method to use. Optional.

Valid keyword values are:

• analytical

• forward difference

• central difference

step size: [real]

Default: none

Selects the step size used when calculating numerical gradients.

algorithm: [string]

Default: scf-diis

Selects the solver to use.

Valid keyword values are:

• scf-diis AO-based self-consistent Roothan-Hall algorithm with direct inversion of the iterative subspace (DIIS) acceleration.

• scf Self-consistent Roothan-Hall algorithm.

• mo-scf-diis MO-based self-consistent Roothan-Hall algorithm with DIIS acceleration. Recommended for multilevel Hartree-Fock (MLHF).

• level-shift-newton-raphson MO-based second-order trust-region step-constrained optimization procedure.

energy threshold: [real]

Default: \(10^{-7}\) (or 1.0d-7)

Energy convergence threshold, as measured with respect to the previous iteration.

residual threshold: [real]

Default: \(10^{-7}\) (or 1.0d-7)

residual threshold \(\tau\). The equations have converged if \(\max \mathbf{G} < \tau\).

gradient response threshold: [real]

Default: \(10^{-7}\) (or 1.0d-7)

Gradient response threshold \(\tau\). The orbital relaxation equations needed to compute the CC level gradient have converged if \(\max \mathbf{G} < \tau\).

storage: [string]

Default: memory

Selects storage of DIIS records.

Valid keyword values are:

• memory Stores DIIS records in memory.

• disk Stores DIIS records on file.

write orbitals

Default: false

If specified, the *mo_coefficients.out file is created and copied to the working directory by eT_launch.

write molden

Default: false

If specified, a molden input file called *.molden is created and copied to the working directory by eT_launch.

crop

Default: false

If specified, the conjugate residual with optimal trial vectors (CROP) version of DIIS will be enabled.

cumulative fock threshold: [real]

Default: \(1.0\) (or 1.0d0)

When the gradient max-norm reaches this threshold, the Fock matrix is built using the difference in the density matrix relative to the previous iteration. When the max-norm exceeds the threshold, the Fock matrix is built directly using the current density matrix.

max iterations: [integer]

Default: \(100\)

The maximum number of iterations. The solver stops if the number of iterations exceeds this number.

diis dimension: [integer]

Default: \(8\)

Number of previous DIIS records to keep.

restart

Default: false

If specified, the solver will attempt to restart from a previous calculation.

skip

Default: false

If specified, orbitals will be read from file, the convergence of the gradient will be checked, but the rest of the SCF solver will be skipped.

ao density guess: [string]

Default: sad

Which atomic orbital density matrix to use as start guess.

Valid keyword values are:

• sad Use the superposition of atomic densities (SAD) guess. This is built on-the-fly by performing spherically averaged UHF calculations on each unique atom (and basis) in the specified molecular system.

• core Use the density obtained by approximating the Fock matrix by its one-electron contribution and performing one Fock diagonalization.

coulomb threshold: [real]

Default: \(10^{-6}*(\text{residual threshold})\)

The threshold for neglecting Coulomb contributions to the two-electron part of the AO Fock matrix.

Default: \(\text{(coulomb threshold)}^2\)

The \(\epsilon\) value for Libint 2. Gives the precision in the electron repulsion integrals.

exchange threshold: [real]

Default: \(10^{-4}*(\text{residual threshold})\)

The threshold for neglecting Exchange contributions to the two-electron part of the AO Fock matrix.

coulomb exchange terms: [string]

Default: collective

Determines if the two-electron part of the Fock matrix (G(D)) is computed at once or if Coulomb and exchange contributions are calculated separately.

Valid keyword values are:

• collective

• separated

population analysis: [string]

Request calculation of population analysis and specify type of analysis.

Valid keyword values are: - mulliken - loewdin - all

rohf coupling parameters: [string]

Default: guest-saunders

Coupling parameters \(\vec{A}, \vec{B}\) for the ROHF orbitals, see for instance J. Chem. Phys. 125, 204110 (2006).

Valid keyword values are:

• guest-saunders : \(\vec{A} = (1/2, 1/2, 1/2), \vec{B}=(1/2, 1/2, 1/2)\)

• mcweeny-diercksen: \(\vec{A} = (1/3, 1/3, 2/3), \vec{B}=(2/3, 1/3, 1/3)\)

• faegri-manne: \(\vec{A} = (1/2, 1, 1/2), \vec{B}=(1/2, 0, 1/2)\)

diabatize orbitals

Request diabatization of orbitals. This will try to make the current converged canonical orbitals as similar as possible as the previous orbitals stored on file. This is typically used with restart, where the goal is to make sure a consistent phase and ordering is maintained at different geometries.

singlet states: [integer]

Specifies the number of singlet excited states to calculate.

energy threshold: [real]

Default: \(10^{-3}\) (or 1.0d-3)

Energy convergence threshold, as measured with respect to the previous iteration. Optional.

max iterations: [integer]

Default: 100

The maximum number of iterations. The solver stops if the number of iterations exceeds this number. Optional.

max reduced dimension: [integer]

Default: 50

The maximal dimension of the reduced space of the Davidson procedure. Optional.

residual threshold: [real]

Default: \(10^{-3}\) (or 1.0d-3)

Threshold of the \(L^{2}\)-norm of the residual vector of the excited state equation. Optional.

restart

Default: false

If specified, the solver will attempt to restart from a previous calculation. Optional.

storage: [string]

Default: memory

Selects storage of excited state records. Optional.

Valid keyword values are:

• memory Stores records in memory.

• disk Stores records on file.

tamm-dancoff

Default: false

Enables the Tamm-Dancoff approximation. Optional.

max iterations: [integer]

Default: 100

The maximum number of iterations. The solver stops if the number of iterations exceeds this number. Optional.

max reduced dimension: [integer]

Default: 100

The maximal dimension of the reduced space of the Davidson procedure. Optional.

residual threshold: [real]

Default: \(10^{-3}\) (or 1.0d-3)

Threshold of the \(L^{2}\)-norm of the residual vector of the response equation. Optional.

frequencies: [list of reals]

Default: None

Frequencies for frequency-dependent polarizabilities. Static polarizabilities are obtained either by specifying frequency zero, or by not giving this keyword. Optional.

print iterations

Default: false

Enables the printing of the iterations of the response solver. Optional.

charge: [integer]

Default: \(0\)

Specifies the charge of the system.

multiplicity: [integer]

Default: \(1\)

Specifies the spin multiplicity of the system.

cartesian gaussians

Enforce cartesian Gaussians basis functions for all atoms. Default for Pople basis sets.

pure gaussians

Enforce spherical Gaussian basis functions for all atoms. Default for all basis sets except Pople basis sets.

write orbitals

Write orbital coefficients to *mo_information.out files when the orbital coefficients change, e.g. when frozen hf or MLCC are used.

file format: [string]

Default: plt

Specify format of the output files containing the grid data. Optional.

Valid options are:

• plt

• cube

grid buffer: [real]

Default: \(2.0\) (or 2.0d0)

Sets the distance between the edge of the grid (x, y, and z direction) and the molecule in Angstrom units. Optional.

grid max: {[real], [real], [real]}

Sets the maximum values of the grid in x, y and z direction in Angstrom. Optional.

grid min: {[real], [real], [real]}

Sets the minimum values of the grid in x, y and z direction in Angstrom. Optional.

grid spacing: [real]

Default: \(0.1\) (or 1.0d-1)

Sets the spacing between grid points for the visualization given in Angstrom units. Optional.

plot cc density

Plots the coupled cluster density. Optional.

plot es densities

Plots the coupled cluster excited state densities for the states to plot. Optional.

plot hf active density

Plots the active HF density in the case of a reduced space calculation. Optional.

plot hf density

Plots the HF density. Optional.

plot hf orbitals: {[integer], [integer], ...}

Plots the canonical orbitals given in the comma separated list. Optional.

plot transition densities

Plots the coupled cluster transition densities for the states to plot. Optional.

states to plot: {[integer], [integer], ...}

List of integers specifying which densities should be plotted.

plot cc orbitals: {[integer], [integer], ...}

Plots the orbitals given in the comma separated list from a CC wave function. Optional.

plot dyson orbitals

Plots the coupled cluster dyson orbitals for the states to plot. Optional.

plot ntos

Request plotting of NTOs for the states to plot. Optional.

plot cntos

Request plotting of CNTOs for the states to plot. Optional.

nto threshold: [real]

Determines the number of NTOs to be plotted. All NTOs will be plotted whose eigenvalues sum up to at least \(1-t\), where t is the given threshold. \(\sum_i e_i \geq 1 - t\)