StrainNiquetHamiltonianParametrization¶

class StrainNiquetHamiltonianParametrization(basis_set, strain_parameters)¶

Class representing the Hamiltonian parametrization for a Slater-Koster type tight binding model with onsite strain corrections.

Parameters:

basis_set (SlaterKosterTable) – An object describing the basis set used for the Slater-Koster calculation.
strain_parameters (StrainNiquetModelParameters) – The parameters for the onsite strain model.

basisSet()¶

Returns the Slater Koster basis set used to construct the environmental independent component of the Hamiltonian and Overlap.

Returns:: The basis set.
Return type:: SlaterKosterTable

pairPotentials()¶

Return the pair potentials. If no pair potentials are available, it returns None.

Returns:: The pair potentials.
Return type:: PairPotential

strainParameters()¶

Returns:: The parameters used to construct the strain correction.
Return type:: StrainNiquetModelParameters

usingOrthogonalBasis()¶

Routine for determining if the Hamiltonian parametrization is using an orthogonal basis set.

Returns:: True if the basis is orthogonal, False otherwise.
Return type:: bool

Usage Examples¶

The following example shows how to setup a parametrization for Silicon and Germanium.

# Create a parametrization using built-in parameters for Silicon and Germanium.
hamiltonian_parametrization = StrainNiquetHamiltonianParametrization(
    basis_set=Niquet.SiGeH_Basis,
    strain_parameters=Niquet.SiGe_StrainParameters)

# Set up a semi-empirical calculator with this parametrization.
calculator = SemiEmpiricalCalculator(
    hamiltonian_parametrization=hamiltonian_parametrization)

Notes¶

This hamiltonian parametrization is an extension to a Slater-Koster nearest neighbr basis including onsite Hamiltonian matrix elements corrections for strained crystal [1].

The available parameter sets in QuantumATK can be found in the following table: NRL style parameters for electronic structure and total energy calculations.