LSCDM

LSCDM = .TRUE. | .FALSE. 

Default: LSCDM

= .FALSE.

Description: LSCDM switches on the selected columns of the density matrix (SCDM) method.

---

The selected columns of the density matrix (SCDM) method works by fitting a unitary matrix $U_{mn\mathbf{k}}$ that transforms the basis from Bloch states $|\psi_{n\mathbf{k}}\rangle$ obtained by VASP to a Wannier basis $|w_{m\mathbf{R}}\rangle$.

$|w_{m\mathbf{R}}\rangle = \sum_{n\mathbf{k}} e^{-i\mathbf{k}\cdot\mathbf{R}} U_{mn\mathbf{k}} |\psi_{n\mathbf{k}}\rangle.$

This is done using a one-shot method through a singular-value decomposition as proposed by A. Dale and L. Lin .

In order to obtain a good Wannierization, a certain level of freedom should be given to the localized orbitals to adequately accommodate the Bloch states. This is controlled by the cutoff function specified by the CUTOFF_TYPE tag and related parameters $\mu$ (CUTOFF_MU) and $\sigma$ (CUTOFF_SIGMA).

Related tags and articles

CUTOFF_TYPE, CUTOFF_MU, CUTOFF_SIGMA

Examples that use this tag