NRLHamiltonianParametrization¶

Included in QATK.Calculators.SemiEmpirical

class NRLHamiltonianParametrization(parameters)¶

Class representing the Hamiltonian parametrization for the Navy Research Laboratory Tight-Binding model.

Parameters:: parameters (NRLTightBindingParameters) – An object describing the parameters used for the in the NRL 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

createCppConfigurationAndBasisSet(configuration, density_cutoff)¶

Returns:

The Slater-Koster basis set used for the Hamiltonian parametrization.

Return type:

class:: NLEngine.SlaterKosterBasisSet

createEnvironmentalParameters(configuration)¶

Returns:

The environmental parameters used for the Hamiltonian parametrization.

Return type:

class:: NLEngine.NRLEnvironmentalParameters

pairPotentials()¶

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

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

parameters()¶

Returns:: A dictionary with all the numerical parameters.
Return type:: dict

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 demonstrates some of the different parameters available for a NRL Hamiltonian parametrization.

# Create a NRL Hamiltonian parametrization with the sp
# parameters for Silicon.
hamiltonian_parametrization = NRLHamiltonianParametrization(
    parameters=NRLParameters.Si_sp)

# NRL parametrization with the parameters for Carbon.
hamiltonian_parametrization = NRLHamiltonianParametrization(
    parameters=NRLParameters.C)

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

Notes¶

The Naval Research Laboratory tight-binding (NRL-TB) method uses distance- and environment-dependent Slater-Koster parameters to provide transferability between different atomic and molecular structures. The NRL parametrization is thoroughly described in [1]. The Slater-Koster model, which the NRL parametrization is based on, is described in Background information.

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