CUTOFF MU: Difference between revisions

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{{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}} specifies a cutoff energy <math>\mu</math> in units of eV for the cutoff function specified by {{TAG|CUTOFF_MU}}.
Description: {{TAG|CUTOFF_MU}} specifies the cutoff energy <math>\mu</math> in eV for the function specified by {{TAG|CUTOFF_MU}}.
   
   
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Corresponds to the cutoff energy of the cutoff function to be used to obtain Wannier functions with the
The value <math>\mu</math> of {{TAG|CUTOFF_MU}} corresponds to the cutoff energy of the cutoff function to be 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 of <math>\mu</math> meaning depends on the {{TAG|CUTOFF_TYPE}} tag.


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 matrix <math>U_{mn\mathbf{k}}</math> from Bloch states to Wannier functions.
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==

Revision as of 10:06, 20 July 2022

CUTOFF_MU = [real] 

Default: CUTOFF_MU = 0.8 * Fermi level of a system with NUM_WANN orbitals occupied

Description: CUTOFF_MU specifies the cutoff energy in eV for the function specified by CUTOFF_MU.


The value of CUTOFF_MU corresponds to the cutoff energy of the cutoff function to be used to obtain Wannier functions with the one-shot method. The of meaning depends on the CUTOFF_TYPE tag.

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.

Related tags and articles

CUTOFF_TYPE, CUTOFF_SIGMA, LSCDM, LOCPROJ

Examples that use this tag