KSPACING: Difference between revisions
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<math>\AA^{-1}</math>. The number of k-points increases when the spacing is decreased. | <math>\AA^{-1}</math>. The number of k-points increases when the spacing is decreased. | ||
The number of k-points in the direction of the first, second and third | The number of k-points in the direction of the first, second and third | ||
reciprocal lattice vector is determined by | reciprocal lattice vector is determined by <math> \mathrm{max}(1, | \vec{b}(i)| / \mathrm{KSPACING} ). </math> | ||
<math> \mathrm{max}(1, | \vec{b}(i)| / \mathrm{KSPACING} ). </math> | |||
These values are rounded to the next integer. The generated grid is either centred at the <math>\Gamma</math> point (e.g. includes the <math>\Gamma</math> point) ({{TAG|KGAMMA}}=''.TRUE.'') or is shifted away | These values are rounded to the next integer. The generated grid is either centred at the <math>\Gamma</math> point (e.g. includes the <math>\Gamma</math> point) ({{TAG|KGAMMA}}=''.TRUE.'') or is shifted away | ||
from the <math>\Gamma</math> point, as usually done for Monkhorst Pack grids ({{TAG|KGAMMA}}=''.FALSE.''). Per default, the grids include the <math>\Gamma</math> point. | from the <math>\Gamma</math> point, as usually done for Monkhorst Pack grids ({{TAG|KGAMMA}}=''.FALSE.''). Per default, the grids include the <math>\Gamma</math> point. | ||
Revision as of 08:55, 28 April 2017
KSPACING = [real]
Default: KSPACING = 0.5
Description: The tag KSPACING determines the number of k-points if the KPOINTS file is not present.
KSPACING is the smallest allowed spacing between k points in units of . The number of k-points increases when the spacing is decreased. The number of k-points in the direction of the first, second and third reciprocal lattice vector is determined by These values are rounded to the next integer. The generated grid is either centred at the point (e.g. includes the point) (KGAMMA=.TRUE.) or is shifted away from the point, as usually done for Monkhorst Pack grids (KGAMMA=.FALSE.). Per default, the grids include the point.