PolarizationOrbital

	PolarizationOrbital
NumericalAccuracyParameters	RandomSpin

Name

PolarizationOrbital — Class for representing the polarization of a confined orbital.

Synopsis

Namespace: NanoLanguage

PolarizationOrbital(base_orbital)

Description

Constructor for the PolarizationOrbital.

PolarizationOrbital Arguments

base_orbital

The confined orbital from which the polarization orbital should be determined.

Type: ConfinedOrbital

Default:


          None

PolarizationOrbital Methods

A PolarizationOrbital object provides the following methods:

This object supports cloning. See the section called “Cloning of ATK Python objects”.
angularMomentum(): Return the angular momentum.
baseOrbital(): Return the confined orbital used for generating the polarization orbital.

Usage Examples

Define a BasisSet for hydrogen.

hydrogen_1s = ConfinedOrbital(
    principal_quantum_number = 1,
    angular_momentum = 0,
    radial_cutoff_radius = 5.28603678847*Bohr,
    confinement_start_radius = 0.8 * 5.28603678847*Bohr,
    additional_charge = 0.0,
    confinement_strength = 20.000*Units.Hartree*Units.Bohr,
    radial_step_size = 0.001*Units.Bohr,
    )

hydrogen_1s_polarization = PolarizationOrbital(hydrogen_1s)

my_hydrogen_basis = BasisSet(
   element = Hydrogen,
   orbitals = [hydrogen_1s, hydrogen_1s_polarization],
   occupations = [1.0 ,0.0],
   pseudopotential = NormConservingPseudoPotential('normconserving/H.LDAPZ.zip'),
   )

Notes

The polarization orbital is generated by perturbing the base_orbital ( $\phi_{l}^\text{base}$ ) by an electric field $E$ pointing in the z-direction.

$\displaystyle [\hat{H}_0 + E z] (\phi_{l}^\text{base}+\delta phi) = \varepsilon_l (\phi_{l}^\text{base}+\delta phi)$

The perturbed orbital $\delta phi$ is calculated by first order perturbation theory and has angular momentum $l+1$ . The polarization orbital is constructed from $\delta phi$

Further information about the basis functions can be found in the section called “LCAO basis set”


NumericalAccuracyParameters		RandomSpin