EffectivePotential

	EffectivePotential
ElectrostaticDifferencePotential	ExternalPotential

Name

EffectivePotential — Class for calculating the effective potential

Synopsis

Namespace: NanoLanguage

EffectivePotential(
configuration,
spin
)

Description

A class for calculating the effective potential for a configuration

EffectivePotential Arguments

configuration

The configuration for which the effective potential should be calculated

Type: MoleculeConfiguration | BulkConfiguration | DeviceConfiguration

spin

The spin for which the potential should be calculated.

Type: Spin.Up | Spin.Down.

Default:


          Spin.Up

EffectivePotential Methods

A EffectivePotential object provides the following methods:

derivatives(x, y, z): Calculate the derivative in the point x,y,z.

x

The cartesian x coordinate.

Type: physical quantity with type length.

y

The cartesian y coordinate.

Type: physical quantity with type length.

z

The cartesian z coordinate.

Type: physical quantity with type length.
evaluate(x, y, z): Evaluate in the point x,y,z

x

The cartesian x coordinate.

Type: physical quantity with type length.

y

The cartesian y coordinate.

Type: physical quantity with type length.

z

The cartesian z coordinate.

Type: physical quantity with type length.
gridCoordinate(i, j, k): Return the coordinate for a given grid index.

i

The grid index in the A direction.

Type: integer

j

The grid index in the B direction.

Type: integer

k

The grid index in the C direction.

Type: integer
nlprint(stream): Method for printing an ASCII table with the effective potential

stream

The stream the effective potential should be written to.
Type: A stream that supports strings being written to using 'write'.
Default: sys.stdout
scale(scale): Scale the field with a double.

scale

The parameter to scale with.

Type: float
shape(): Query function for getting the shape of the data.
spin(): Query method for getting the spin
toArray(): Return the values of the grid as a numpy array slicing off any units.
unit(): Get the unit of the data in the grid.
unitCell(): Return the unit cell for the grid.
volumeElement(): Get the volume element of the grid.

Usage Examples

Calculate the effective potential and save it to a file

# Set up configuration
molecule_configuration = MoleculeConfiguration(
    elements=[Nitrogen, Hydrogen, Hydrogen, Hydrogen],
    cartesian_coordinates=[[ 0.     ,  0.      ,  0.124001],
                           [ 0.     ,  0.941173, -0.289336],
                           [ 0.81508, -0.470587, -0.289336],
                           [-0.81508, -0.470587, -0.289336]]*Angstrom 
    )

# Define the calculator
calculator = LCAOCalculator()
molecule_configuration.setCalculator(calculator)

# Calculate and save the effective potential
effective_potential = EffectivePotential(molecule_configuration)
nlsave('results.nc', effective_potential)

nh3_effective_potential.py

For examples on how to average and handle 3-d grids, see the examples for ElectronDifferenceDensity and ElectrostaticDifferencePotential.

Notes

EffectivePotential, returns the effective potential of a DFT calculation. The effective potential refers to a fictitious system of non-interacting electrons. It is the potential that would cause this non-interacting system to reproduce the electron density of the true system of interacting electrons.
To export the grid data of an effective potential, use the method nlprint.
Calculation of the effective potential is not supported for the HuckelCalculator.


ElectrostaticDifferencePotential		ExternalPotential