NRLHamiltonianParametrization

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 Slater-Koster 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
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 [PM03]. 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.

[PM03]D. A. Papaconstantopoulos and M. J. Mehl. The Slater-Koster tight-binding method: a computationally efficient and accurate approach. J. Phys. Condens. Matter, 15(10):R413–R440, 2003. doi:10.1088/0953-8984/15/10/201.