KPOINT_BSE

KPOINT_BSE = [integer] (optionally [integer],[integer],[integer]) 

Description: KPOINT_BSE specifies the k-point index at which VASP calculates the dielectric matrix.

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In the simplest form, one can specify

  KPOINT_BSE = index_of_k-point

Select the desired k point from the list of k points in the OUTCAR file. Additionally, a shift by an arbitrary reciprocal lattice vector can be supplied by specifying three additional integer numbers:

 KPOINT_BSE = index_of_k-point  n1 n2 n3

This allows calculating the dielectric function at a k point outside of the first Brillouin zone corresponding to

$\bold{k} + n_{1} \bold{b}_{1}+ n_{2} \bold{b}_{2} + n_{3} \bold{b}_{3}$

where $\bold{b}_{i}$ are the reciprocal-lattice vectors of the unit cell.

Warning: We strongly recommend using ANTIRES=2 for the finite wavevector calculations. The Tamm-Dancoff approximation can lead to unphysical results for the dielectric function at a finite wavevector.

Related tags and articles

BSE calculations

Examples that use this tag

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