Assume that we have a cube file that contains Ni * Nj * Nk
points, and an origin at 0, 0, 0
, where are the data points actually located?
Let's say the grid spacing along each direction is di, dj, dk
in crystal coordinates (so di = 1 / (Ni - 1)
).
Are the data points located at 0, di, 2 * di, ..., ... Nx * di
or 0.5 * di, 1.5 * di, ..., (Nx + 0.5) * di
(and correspondingly for other axes)? Meaning, is the sampled data at the origin and corresponding gridpoints, or are they between the gridpoints, similar to a mean value for voxels?
References (that may be useful, but don't answer the question above definitively):
- http://paulbourke.net/dataformats/cube/ A good exposition about the cube file format.
- https://gitlab.com/ase/ase/-/blob/master/ase/io/cube.py#L69 ASE's cube file reader.
- https://h5cube-spec.readthedocs.io/en/latest/cubeformat.html Another attempt at the specs of the cube file format.