Model Method Electronic¶

Purpose: Electronic method subclasses branching from ModelMethodElectronic

In scope:

Electronic-method inheritance rooted at ModelMethodElectronic
Ground-state electronic methods (DFT, HartreeFock, coupled-cluster, CI, perturbative approaches)
Tight-binding family (TB, xTB, Wannier, SlaterKoster)
Excited-state methodology branch (ExcitedStateMethodology, Screening, GW, BSE, TDDFT)
Core-hole and many-body electronic methods (CoreHoleSpectra, DMFT)

Relationship map¶

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classDiagram
    class BSE
    class ConfigurationInteraction
    class CoreHoleSpectra
    class CoupledCluster
    class DFT
    class DMFT
    class ExcitedStateMethodology
    class GW
    class HartreeFock
    class ModelMethodElectronic
    class PerturbationMethod
    class Screening
    class SlaterKoster
    class TB
    class TDDFT
    class Wannier
    class xTB
    ExcitedStateMethodology <|-- BSE
    ModelMethodElectronic <|-- ConfigurationInteraction
    ModelMethodElectronic <|-- CoreHoleSpectra
    ModelMethodElectronic <|-- CoupledCluster
    ModelMethodElectronic <|-- DFT
    ModelMethodElectronic <|-- DMFT
    ModelMethodElectronic <|-- ExcitedStateMethodology
    ExcitedStateMethodology <|-- GW
    ModelMethodElectronic <|-- HartreeFock
    ModelMethodElectronic <|-- PerturbationMethod
    ExcitedStateMethodology <|-- Screening
    TB <|-- SlaterKoster
    ModelMethodElectronic <|-- TB
    ExcitedStateMethodology <|-- TDDFT
    TB <|-- Wannier
    TB <|-- xTB

Legend

Parent <|-- Child inheritance (Child extends Parent)

Key sections¶

Section	Description	MetaInfo
`ModelMethodElectronic`	A base section used to define the parameters of a model Hamiltonian used in electronic structure calculations (TB, DFT, GW, BSE, DMFT, etc).	Open in MetaInfo browser
`DFT`	A base section used to define the parameters used in a density functional theory (DFT) calculation.	Open in MetaInfo browser
`TB`	A base section containing the parameters pertaining to a tight-binding (TB) model calculation.	Open in MetaInfo browser
`xTB`	A base section used to define the parameters used in an extended tight-binding (xTB) calculation.	Open in MetaInfo browser
`Wannier`	A base section used to define the parameters used in a Wannier tight-binding fitting.	Open in MetaInfo browser
`SlaterKoster`	A base section used to define the parameters used in a Slater-Koster tight-binding fitting.	Open in MetaInfo browser
`ExcitedStateMethodology`	A base section used to define the parameters typical of excited-state calculations.	Open in MetaInfo browser
`Screening`	A base section used to define the parameters that define the calculation of screening.	Open in MetaInfo browser
`GW`	A base section used to define the parameters of a GW calculation.	Open in MetaInfo browser
`BSE`	A base section used to define the parameters of a BSE calculation.	Open in MetaInfo browser
`TDDFT`	Time-dependent density functional theory settings.	Open in MetaInfo browser
`HartreeFock`	Defines a Hartree-Fock (HF) calculation.	Open in MetaInfo browser
`CoupledCluster`	A base section used to define the parameters of a Coupled Cluster calculation.	Open in MetaInfo browser
`ConfigurationInteraction`	Single-reference Configuration Interaction (CI) methods using atom-centered basis sets.	Open in MetaInfo browser
`PerturbationMethod`		Open in MetaInfo browser
`CoreHoleSpectra`	A base section used to define the parameters used in a core-hole spectra calculation.	Open in MetaInfo browser
`DMFT`	A base section used to define the parameters of a DMFT calculation.	Open in MetaInfo browser

Quantities by section¶

`ModelMethodElectronic`¶

Quantity	Type	Description
`is_spin_polarized`	m_bool(bool)	If the simulation is done considering the spin degrees of freedom (then there are two spin channels, 'down' and 'up') or not.
`determinant`	Enum	The spin-coupling form of the determinant used for the The spin-coupling form of the determinant used for the self-consistent field (SCF) calculation. - restricted (RHF/RKS): α and β electrons share the same spatial orbitals - unrestricted (UHF/UKS): α and β orbitals are optimized independently - restricted-open-shell (ROHF/ROKS): closed-shell core with spin-unpaired electrons sharing spatial orbitals in the open-shell manifold

`DFT`¶

Quantity	Type	Description
`jacobs_ladder`	Enum	Highest Jacob's ladder rung present among XC components. Highest Jacob's ladder rung present among XC components. See: - https://doi.org/10.1063/1.1390175 (original paper) - https://doi.org/10.1103/PhysRevLett.91.146401 (meta-GGA) - https://doi.org/10.1063/1.1904565 (hyper-GGA)

`TB`¶

Quantity	Type	Description
`type`	Enum	Tight-binding model Hamiltonian type. Tight-binding model Hamiltonian type. The default is set to `'unavailable'` in case none of the standard types can be recognized. These can be: \| Value \| Reference \| \| --------- \| ----------------------- \| \| `'DFTB'` \| https://en.wikipedia.org/wiki/DFTB \| \| `'xTB'` \| https://xtb-docs.readthedocs.io/en/latest/ \| \| `'Wannier'` \| https://www.wanniertools.org/theory/tight-binding-model/ \| \| `'SlaterKoster'` \| https://journals.aps.org/pr/abstract/10.1103/PhysRev.94.1498 \| \| `'unavailable'` \| - \|
`n_orbitals_per_atom`	m_int32(int32)	Number of orbitals per atom in the unit cell used as a basis to obtain the `TB` model. This quantity is resolved from `orbitals_ref` via normalization.
`n_atoms_per_unit_cell`	m_int32(int32)	Number of atoms per unit cell relevant for the `TB` model. This quantity is resolved from `n_total_orbitals` and `n_orbitals_per_atom` via normalization.
`n_total_orbitals`	m_int32(int32)	Total number of orbitals used as a basis to obtain the `TB` model. This quantity is parsed by the specific parsing code. This is related with `n_orbitals_per_atom` and `n_atoms_per_unit_cell` as: `n_total_orbitals` = `n_orbitals_per_atom` * `n_atoms_per_unit_cell`
`orbitals_ref`	(shape: ['n_orbitals_per_atom'])	References to the `ElectronicState` that contain system's the orbitals (with a mapping to each atom) relevant for the `TB` model. References to the `ElectronicState` that contain system's the orbitals (with a mapping to each atom) relevant for the `TB` model. This quantity is resolved from normalization when the active atoms sub-systems `model_system.model_system[*]` are populated. The relevant orbitals for the TB model are the `'pz'` ones for each `'C'` atom. Then, we define: `orbitals_ref= [ElectronicState('pz'), ElectronicState('pz')]` The relevant atoms information can be accessed from the parent AtomsState sections: `<br>atom_state = orbitals_ref[i].m_parent<br>index = orbitals_ref[i].m_parent_index<br>atom_position = orbitals_ref[i].m_parent.m_parent.positions[index]<br>`

`xTB`¶

This section has no direct quantities.

`Wannier`¶

Quantity	Type	Description
`is_maximally_localized`	m_bool(bool)	If the projected orbitals are maximally localized or just a single-shot projection.
`localization_type`	Enum	Localization type of the Wannier orbitals.
`n_bloch_bands`	m_int32(int32)	Number of input Bloch bands to calculate the projection matrix.
`energy_window_outer`	m_float64(float64) (shape: [2])	Bottom and top of the outer energy window used for the projection.
`energy_window_inner`	m_float64(float64) (shape: [2])	Bottom and top of the inner energy window used for the projection.

`SlaterKoster`¶

This section has no direct quantities.

`ExcitedStateMethodology`¶

Quantity	Type	Description
`n_states`	m_int32(int32)	Number of states used to calculate the excitations.
`n_empty_states`	m_int32(int32)	Number of empty states used to calculate the excitations. This quantity is complementary to `n_states`.
`broadening`	m_float64(float64)	Lifetime broadening applied to the spectra in full-width at half maximum for excited-state calculations.

`Screening`¶

Quantity	Type	Description
`dielectric_infinity`	m_int32(int32)	Value of the static dielectric constant at infinite q. For metals, this is infinite (or a very large value), while for insulators is finite.

`GW`¶

Quantity	Type	Description
`type`	Enum	GW Hedin's self-consistency cycle: GW Hedin's self-consistency cycle: \| Name \| Description \| Reference \| \| --------- \| -------------------------------- \| --------------------- \| \| `'G0W0'` \| single-shot \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.74.035101 \| \| `'scGW'` \| self-consistent G and W \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.75.235102 \| \| `'scGW0'` \| self-consistent G with fixed W0 \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.54.8411 \| \| `'scG0W'` \| self-consistent W with fixed G0 \| - \| \| `'ev-scGW0'` \| eigenvalues self-consistent G with fixed W0 \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.34.5390 \| \| `'ev-scGW'` \| eigenvalues self-consistent G and W \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.74.045102 \| \| `'qp-scGW0'` \| quasiparticle self-consistent G with fixed W0 \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.76.115109 \| \| `'qp-scGW'` \| quasiparticle self-consistent G and W \| https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.96.226402 \|
`analytical_continuation`	Enum	Analytical continuation approximations of the GW self-energy: Analytical continuation approximations of the GW self-energy: \| Name \| Description \| Reference \| \| -------------- \| ------------------- \| -------------------------------- \| \| `'pade'` \| Pade's approximant \| https://link.springer.com/article/10.1007/BF00655090 \| \| `'contour_deformation'` \| Contour deformation \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.67.155208 \| \| `'ppm_GodbyNeeds'` \| Godby-Needs plasmon-pole model \| https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.62.1169 \| \| `'ppm_HybertsenLouie'` \| Hybertsen and Louie plasmon-pole model \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.34.5390 \| \| `'ppm_vonderLindenHorsh'` \| von der Linden and P. Horsh plasmon-pole model \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.37.8351 \| \| `'ppm_FaridEngel'` \| Farid and Engel plasmon-pole model \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.47.15931 \| \| `'multi_pole'` \| Multi-pole fitting \| https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.74.1827 \|
`interval_qp_corrections`	m_int32(int32) (shape: [2])	Band indices (in an interval) for which the GW quasiparticle corrections are calculated.
`screening_ref`		Reference to the `Screening` section that the GW calculation used to obtain the screened Coulomb interactions.

`BSE`¶

Quantity	Type	Description
`type`	Enum	Type of the BSE Hamiltonian solved: Type of the BSE Hamiltonian solved: H_BSE = H_diagonal + 2 * gx * Hx - gc * Hc Online resources for the theory: - http://exciting.wikidot.com/carbon-excited-states-from-bse#toc1 - https://www.vasp.at/wiki/index.php/Bethe-Salpeter-equations_calculations - https://docs.abinit.org/theory/bse/ - https://www.yambo-code.eu/wiki/index.php/Bethe-Salpeter_kernel \| Name \| Description \| \| --------- \| ----------------------- \| \| `'Singlet'` \| gx = 1, gc = 1 \| \| `'Triplet'` \| gx = 0, gc = 1 \| \| `'IP'` \| Independent-particle approach \| \| `'RPA'` \| Random Phase Approximation \|
`solver`	Enum	Solver algotithm used to diagonalize the BSE Hamiltonian. Solver algotithm used to diagonalize the BSE Hamiltonian. \| Name \| Description \| Reference \| \| --------- \| ----------------------- \| ----------- \| \| `'Full-diagonalization'` \| Full diagonalization of the BSE Hamiltonian \| - \| \| `'Lanczos-Haydock'` \| Subspace iterative Lanczos-Haydock algorithm \| https://doi.org/10.1103/PhysRevB.59.5441 \| \| `'GMRES'` \| Generalized minimal residual method \| https://doi.org/10.1137/0907058 \| \| `'SLEPc'` \| Scalable Library for Eigenvalue Problem Computations \| https://slepc.upv.es/ \| \| `'TDA'` \| Tamm-Dancoff approximation \| https://doi.org/10.1016/S0009-2614(99)01149-5 \|
`screening_ref`		Reference to the `Screening` section that the BSE calculation used to obtain the screened Coulomb interactions.

`TDDFT`¶

Quantity	Type	Description
`type`	Enum	TDDFT flavour: - linear_response: frequency-domain response (Casida/Sternheimer/Liouv.-Lanczos) - real_time: explicit time propagation under a perturbation
`solver`	Enum	Numerical formulation / driver: - Casida, Sternheimer, Liouville-Lanczos: linear-response formulations - propagation: real-time propagation formulation
`approximation`	Enum	Approximation level of the TDDFT equations. - full: full linear-response TDDFT (includes coupling terms) - TDA : Tamm-Dancoff approximation (linear-response only)
`field_polarization_ref`		External field / polarization used to drive the response or propagation.
`target_property`	Enum	Intended spectral/response target of the TDDFT input.

`HartreeFock`¶

Quantity	Type	Description
`type`	Enum	The type of HF determinant.

`CoupledCluster`¶

Quantity	Type	Description
`type`	m_str(str)	String labeling the Coupled Cluster flavor (e.g., CC2, CC3, CCD, CCSD, CCSDT, etc.). String labeling the Coupled Cluster flavor (e.g., CC2, CC3, CCD, CCSD, CCSDT, etc.). If a known standard approach, it might match these examples: - CC2, CC3 : approximate CC models (commonly used for excited-state calculations) - CCD : Coupled Cluster Doubles - CCSD : Singles and Doubles - CCSDT : Singles, Doubles, and Triples - CCSDTQ : Singles, Doubles, Triples, and Quadruples By default, the "perturbative corrections" like (T) are not included in this string.
`excitation_order`	m_int32(int32) (shape: ['*'])	The excitation orders explicitly included in the cluster operator, e.g. The excitation orders explicitly included in the cluster operator, e.g. [1,2] for CCSD. - 1 = singles - 2 = doubles - 3 = triples - 4 = quadruples, etc. Example: CCSDT => [1, 2, 3].
`perturbative_correction_order`	m_int32(int32) (shape: ['*'])	The excitation orders included only in a perturbative manner. For instance, in CCSD(T), singles and doubles are solved iteratively, while triples appear as a perturbative correction => [3].
`perturbative_correction`	Enum	Label for the perturbative corrections: Label for the perturbative corrections: - '(T)' : standard perturbative triples - '[T]' : Brueckner-based or other variant - '(T0)' : approximate version of (T) - '[T0]' : approximate, typically for Brueckner references - '(Q)' : perturbative quadruples, e.g., CCSDT(Q)
`explicit_correlation`	Enum	Explicit correlation treatment. Explicit correlation treatment. These methods introduce the interelectronic distance coordinate directly into the wavefunction to treat dynamical electron correlation. It can be added linearly (R12) or exponentially (F12).

`ConfigurationInteraction`¶

Quantity	Type	Description
`type`	Enum	CI variant to employ
`excitation_order`	m_int32(int32) (shape: ['*'])	List of excitation orders included in the CI expansion (1=singles, 2=doubles, 3=triples, 4=quadruples, …).

`PerturbationMethod`¶

Quantity	Type	Description
`type`	Enum	Perturbation approach. Perturbation approach. The abbreviations stand for: \| Abbreviation \| Description \| \| ------------ \| ----------- \| \| `'MP'` \| Møller-Plesset \| \| `'RS'` \| Rayleigh-Schrödinger \| \| `'BW'` \| Brillouin-Wigner \|
`order`	m_int32(int32)	Order up to which the perturbation is expanded.
`density`	Enum	unrelaxed density: no orbital-response terms. relaxed density : incorporates orbital relaxation.
`spin_component_scaling`	Enum	Spin-component scaling approach for perturbation methods: Spin-component scaling approach for perturbation methods: - SCS : spin-component scaled (Grimme's approach, https://doi.org/10.1002/wcms.1110) - SOS : spin-opposite scaled - custom: user-defined scaling factors Typically used for MP2; SCS/SOS variants also exist for some approximate CC models.

`CoreHoleSpectra`¶

Quantity	Type	Description
`type`	Enum	Type of the CoreHole excitation spectra calculated, either "absorption" or "emission".
`edge`	Enum	Edge label of the excited core-hole. This is obtained by normalization by using `core_hole_ref`.
`core_hole_ref`		Reference to the `CoreHole` section that contains the information of the edge of the excited core-hole.
`excited_state_method_ref`		Reference to the `ModelMethodElectronic` section (e.g., `DFT` or `BSE`) that was used to obtain the core-hole spectra.

`DMFT`¶

Quantity	Type	Description
`impurity_solver`	Enum	Impurity solver method used in the DMFT loop: Impurity solver method used in the DMFT loop: \| Name \| Reference \| \| ----------------- \| ------------------------------------ \| \| `'CT-INT'` \| https://link.springer.com/article/10.1134/1.1800216 \| \| `'CT-HYB'` \| https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.97.076405 \| \| `'CT-AUX'` \| https://iopscience.iop.org/article/10.1209/0295-5075/82/57003 \| \| `'ED'` \| https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.72.1545 \| \| `'NRG'` \| https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.80.395 \| \| `'MPS'` \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.045144 \| \| `'IPT'` \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.45.6479 \| \| `'NCA'` \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.47.3553 \| \| `'OCA'` \| https://journals.aps.org/prb/abstract/10.1103/PhysRevB.47.3553 \| \| `'slave_bosons'` \| https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.57.1362 \| \| `'hubbard_I'` \| https://iopscience.iop.org/article/10.1088/0953-8984/24/7/075604 \|
`n_impurities`	m_int32(int32)	Number of impurities mapped from the correlated atoms in the unit cell. This defines whether the DMFT calculation is done in a single-impurity or multi-impurity run.
`n_orbitals`	m_int32(int32) (shape: ['n_impurities'])	Number of correlated orbitals per impurity.
`orbitals_ref`	(shape: ['n_orbitals'])	References to the `ElectronicState` sections that contain the orbitals informati... References to the `ElectronicState` sections that contain the orbitals information which are relevant for the `DMFT` calculation. Example: hydrogenated graphene with 3 atoms in the unit cell. The full list of `AtomsState` would be [ AtomsState(chemical_symbol='C', electronic_state=ElectronicState(basis_orbitals=[SphericalSymmetryState('s'), SphericalSymmetryState('px'), SphericalSymmetryState('py'), SphericalSymmetryState('pz')])), AtomsState(chemical_symbol='C', electronic_state=ElectronicState(basis_orbitals=[SphericalSymmetryState('s'), SphericalSymmetryState('px'), SphericalSymmetryState('py'), SphericalSymmetryState('pz')])), AtomsState(chemical_symbol='H', electronic_state=ElectronicState(basis_orbitals=[SphericalSymmetryState('s')])), ] The relevant orbitals for the TB model are the `'pz'` ones for each `'C'` atom. Then, we define: orbitals_ref = [ElectronicState('pz'), ElectronicState('pz')] The relevant impurities information can be accesed from the parent AtomsState sections: impurity_state = orbitals_ref[i].m_parent index = orbitals_ref[i].m_parent_index impurity_position = orbitals_ref[i].m_parent.m_parent.positions[index]
`n_electrons`	m_float64(float64) (shape: ['n_impurities'])	Initial number of valence electrons per impurity.
`inverse_temperature`	m_float64(float64)	Inverse temperature = 1/(kB*T).
`magnetic_state`	Enum	Magnetic state in which the DMFT calculation is done. This quantity can be obtained from `orbitals_ref` and their spin state.

Model Method Electronic¶

Relationship map¶

Key sections¶

Quantities by section¶

ModelMethodElectronic¶

DFT¶

TB¶

xTB¶

Wannier¶

SlaterKoster¶

ExcitedStateMethodology¶

Screening¶

GW¶

BSE¶

TDDFT¶

HartreeFock¶

CoupledCluster¶

ConfigurationInteraction¶

PerturbationMethod¶

CoreHoleSpectra¶

DMFT¶