KSPACING

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 $\mathrm {\AA} ^{-1}$ . 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 $N=\mathrm {max} (1,|{\vec {b}}_{i}|/\mathrm {KSPACING} ).$ These values are rounded to the next integer greater than or equal to $N$ . In this equation ${\vec {b}}_{i}$ are the reciprocal lattice vectors ${\vec {b}}_{i}{\vec {a}}_{j}=2\pi \delta _{ij}$ . The generated grid is either centred at the $\Gamma$ point (e.g. includes the $\Gamma$ point) (KGAMMA=.TRUE.) or is shifted away from the $\Gamma$ point, as usually done for Monkhorst Pack grids (KGAMMA=.FALSE.). The default is to include the $\Gamma$ point.

Note: This implementation is not entirely consistent with the automatic k-point generation (Mode=A) used in the KPOINTS file. If the k-points are generated using the automatic mode in the KPOINTS file, $N$ is calculated as $N=\mathrm {max} (1,|{\vec {b}}_{i}|/(2\pi \times \mathrm {KSPACING} ))$ and rounding is to the nearest integer. We recommend to use the KSPACING tag in the INCAR file and to avoid using the automatic mode via the KPOINTS file.