# GRID

Configuration options for the grid library, which performs e.g. the collocate and integrate of the GPW method. [Edit on GitHub]

## Keywords

- APPLY_CUTOFF

- BACKEND

- VALIDATE

## Keyword descriptions

APPLY_CUTOFF: logical = T

  Lone keyword: `T`

  When enabled the cpu backend apply a spherical cutoff on the top of the cube. There is a performance penalty using it in combination with the cpu backend but it is on by default for the regtests [Edit on GitHub]

BACKEND: enum = AUTO

  Valid values:

  - `AUTO` Let the grid library pick the backend automatically

  - `REFERENCE` Reference backend implementation

  - `CPU` Optimized CPU backend

  - `DGEMM` Alternative CPU backend based on DGEMM

  - `GPU` GPU backend optimized for CUDA that also supports HIP

  - `HIP` HIP backend optimized for ROCm

  Selects the backed used by the grid library. [Edit on GitHub]

VALIDATE: logical = F

  Lone keyword: `T`

  When enabled the reference backend is run in shadow mode and its results are compared with those from the selected backend. If the two results differ by too much then the calculation is aborted. [Edit on GitHub]