# DFTHalfParameters¶

class DFTHalfParameters(element, half_shell_n=None, half_shell_l=None, fractional_charge=None, cutoff_radius=None, all_electron=None)

Class for representing the DFT-1/2 parameters set for a given element in DFT.

Parameters: element (PeriodicTableElement) – The element for which the DFT-1/2 parameters are defined. half_shell_n (int) – Integer specifying from which n-shell to remove the fractional charge. Default: The last occupied shell. half_shell_l (int) – Integer specifying from which l-shell to remove the fractional charge. Default: The last occupied shell. fractional_charge (float | list of floats) – Either a float value between 0 and 1 specifying how much charge to remove from the atomic calculation, or a list of two floats specifying how much charge to remove from up and down spin. Default: [0.5, 0] cutoff_radius (PhysicalQuantity of type length) – Radius specifying the radial cutoff. Default: 2.0 * Bohr all_electron (bool) – Boolean to determine whether to use an all-electron calculation (True) or a pseudopotential calculation (False). Default: True
allElectron()

Return the all_electron value.

Returns: Boolean to determine whether to use an all-electron calculation (True) or a pseudopotential calculation (False). bool
cutoffRadius()

Returns: The cutoff radius. PhysicalQuantity of type length
element()

Return the element for which the DFT-1/2 parameters are defined.

Returns: The atomic element. PeriodicTableElement
fractionalCharge()

Return the fractional_charge value.

Returns: The fractional charge to remove. It will either be a float or a list of two floats where the latter case specifies the up and down spin fractional charges to remove. float | list of floats
halfShellL()

Return the half_shell_l value.

Returns: The integer for the angular quantum number of the state to remove a fractional electron from. int
halfShellN()

Return the half_shell_n value.

Returns: The integer for the principal quantum number of the state to remove a fractional electron from. int

## Usage Examples¶

Define a BasisSet for Silicon with a set of custom DFTHalfParameters:

dft_half_parameters = DFTHalfParameters(
element=Silicon,
fractional_charge=[0.2, 0.0],

Adding a set of DFTHalfParameters to a BasisSet will only have an effect on the calculation if the ExchangeCorrelation has been defined with dft_half_enabled = True.