CUTOFF_MU

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 $\mu$ in eV for the function specified by CUTOFF_MU.

The value $\mu$ 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 $\mu$ 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 $U_{mn\mathbf{k}}$ from Bloch states to Wannier functions.

Tip: Careful tuning of this parameter is required to obtain a good Wannierization.

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