CUTOFF MU: Difference between revisions
(Document support for spin-polarized case) |
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The meaning of <math>\mu</math> depends on the {{TAG|CUTOFF_TYPE}} tag. | The meaning of <math>\mu</math> depends on the {{TAG|CUTOFF_TYPE}} tag. | ||
For spin-polarized calculations ({{ | For spin-polarized calculations ({{TAG|ISPIN|2}}), two values can be specified for {{TAG|CUTOFF_MU}}, one for each spin channel. | ||
If only a single value is specified, it will be used for both spin channels. | If only a single value is specified, it will be used for both spin channels. | ||
Latest revision as of 08:01, 24 October 2025
CUTOFF_MU = [real] ( [real] )
| Default: CUTOFF_MU | = 0.8 * Fermi level of a system with NUM_WANN orbitals occupied |
Description: CUTOFF_MU specifies the energy cutoff [math]\displaystyle{ \mu }[/math] in eV for the function specified by CUTOFF_MU.
The value [math]\displaystyle{ \mu }[/math] of CUTOFF_MU corresponds to the energy cutoff of the cutoff function used to obtain Wannier functions with the one-shot method. The meaning of [math]\displaystyle{ \mu }[/math] depends on the CUTOFF_TYPE tag.
For spin-polarized calculations (ISPIN = 2), two values can be specified for CUTOFF_MU, one for each spin channel.
If only a single value is specified, it will be used for both spin channels.
The default value is computed by first determining the Fermi level of the system if it had NUM_WANN orbitals occupied and multiplying by 0.8. This gives reasonable freedom to determine the unitary transformation [math]\displaystyle{ U_{mn\mathbf{k}} }[/math] from Bloch states to Wannier functions.
| Tip: Careful tuning of this parameter is required to obtain a good Wannierization. |