kspace

This keyword selects the method for computing the reciprocal-space electrostatic energy.

Syntax

kspace ewald
kspace pppm [spacing]

The default method is pppm (particle-particle particle-mesh). Its optional spacing parameter sets the maximum mesh spacing in Angstrom (default: 1.0; allowed range: 0.2 to 2.0, inclusive). Smaller values give finer meshes at a higher computational cost.

The mesh is chosen automatically and grows as needed when the box changes. It does not shrink. The actual spacing may be smaller than the requested value.

Specify kspace at most once in run.in, before the first run.

Example

To use Ewald:

kspace ewald

To request a PPPM spacing of at most 1.5 Angstrom use:

kspace pppm 1.5