CUTOFF MU: Difference between revisions
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{{TAGDEF|CUTOFF_MU| [real]}} | {{DISPLAYTITLE:CUTOFF_MU}} | ||
{{TAGDEF|CUTOFF_MU| [real] ( [real] )}} | |||
{{DEF|CUTOFF_MU| 0.8 * Fermi level of a system with {{TAG|NUM_WANN}} orbitals occupied|}} | {{DEF|CUTOFF_MU| 0.8 * Fermi level of a system with {{TAG|NUM_WANN}} orbitals occupied|}} | ||
Description: {{TAG|CUTOFF_MU}} | Description: {{TAG|CUTOFF_MU}} specifies the energy cutoff <math>\mu</math> in eV for the function specified by {{TAG|CUTOFF_MU}}. | ||
---- | ---- | ||
The value <math>\mu</math> of {{TAG|CUTOFF_MU}} corresponds to the energy cutoff of the cutoff function used to obtain Wannier functions with the | |||
[[Wannier_functions#One-shot_single_value_decomposition (SVD)| one-shot method]]. | [[Wannier_functions#One-shot_single_value_decomposition (SVD)| one-shot method]]. | ||
The meaning depends on the {{TAG|CUTOFF_TYPE}} tag. | The meaning of <math>\mu</math> depends on the {{TAG|CUTOFF_TYPE}} tag. | ||
For spin-polarized calculations ({{TAGO|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. | |||
The default value is computed by first determining the Fermi level | The default value is computed by first determining the Fermi level | ||
of the system if it had {{TAG|NUM_WANN}} orbitals occupied and multiplying by 0.8. This gives reasonable freedom to determine the unitary | of the system if it had {{TAG|NUM_WANN}} orbitals occupied and multiplying by 0.8. This gives reasonable freedom to determine the unitary transformation <math>U_{mn\mathbf{k}}</math> from Bloch states to Wannier functions. | ||
{{NB|tip|Careful tuning of this parameter is required to obtain a good Wannierization.}} | |||
Careful tuning of this parameter is required to obtain a good Wannierization. | |||
== Related tags and articles== | == Related tags and articles== | ||
{{TAG|CUTOFF_TYPE}}, | {{TAG|CUTOFF_TYPE}}, | ||
{{TAG|CUTOFF_SIGMA}}, | {{TAG|CUTOFF_SIGMA}}, | ||
{{TAG|LSCDM}}, | {{TAG|LSCDM}}, | ||
Latest revision as of 14:00, 27 June 2024
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 in eV for the function specified by CUTOFF_MU.
The value 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 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 from Bloch states to Wannier functions.
| Tip: Careful tuning of this parameter is required to obtain a good Wannierization. |