qcmethod

Quantum chemistry methods module.

class daltonproject.qcmethod.QCMethod(qc_method: str, xc_functional: Optional[str] = None, coulomb: Optional[str] = None, exchange: Optional[str] = None, scf_threshold: Optional[float] = None, exact_exchange: Optional[float] = None, environment: Optional[str] = None)

Specifies the QC method, including all associated settings.

complete_active_space(num_active_electrons: int, num_cas_orbitals: Union[List[int], int], num_inactive_orbitals: Union[List[int], int]) → None

Specify complete active space.

Parameters

• num_active_electrons – Number of active electrons. // Maybe this should be inferred just from the num_inactive_orbitals?

• num_cas_orbitals – List of number of orbitals in complete active space.

• num_inactive_orbitals – List of number of inactive (doubly occupied) orbitals.

coulomb(coulomb: str) → None

Specify name of Coulomb approximation.

Parameters

coulomb – Name of approximation to use for the Coulomb contribution.

environment(environment)

Specify the environment model.

Parameters

environment – Name of the environment model.

exact_exchange(exact_exchange: float) → None

Specify amount of Hartree-Fock-like exchange in DFT calculation.

Parameters

exact_exchange – Coefficient specifying amount of Hartree-Fock-like exchange, where 0.0 is only DFT exchange and 1.0 is only Hartree-Fock-like exchange.

exchange(exchange: str) → None

Specify name of exchange approximation.

Parameters

exchange – Name of approximation to use for the exchange contribution.

input_orbital_coefficients(orbitals: Union[ndarray, Dict[int, ndarray]]) → None

Specify starting guess for orbitals.

Parameters

orbitals – Orbital coefficients.

integral_family(integral_family: bool) → None

Specify if internal integral intermediates should be reused for integral_family basis sets.

Parameters

integral_family – Reuse internal integral intermediates for shared-exponent angular blocks.

qc_method(qc_method: str) → None

Specify quantum chemistry method.

Parameters

qc_method – Name of quantum chemical method.

range_separation_parameter(mu: float) → None

Specify value of range separation parameter.

The range separation parameter is used in srDFT.

Parameters

mu – Range separation parameter in unit of a.u.^-1.

scf_threshold(threshold: float) → None

Specify convergence threshold for SCF calculations.

Parameters

threshold – Threshold for SCF convergence in Hartree.

target_state(state: int, symmetry: int = 1) → None

Specify target state for state-specific calculations.

Parameters

• state – Which state to be targeted, counting from 1.

• symmetry – Symmetry of the target state.

xc_functional(xc_functional: str) → None

Specify exchange-correlation functional to use with DFT methods.

Parameters

xc_functional – Name of exchange-correlation functional.