# calcvoid

Calculates Voids and Channels.

[radii file name] [all atoms/selected atoms] [-d=0] [-p] [-r=0.2 Å]

Calculates and displays the structure map. Also calculates the largest channels along crystallographic directions and the packing index.

• -d: extra distance from the surface (added to the atomic radii)
• -p: precise calculation where each map voxel is tested. The default quick algorithm uses the atom masks to find the volume occupied by the molecule. The precise calculation is vectorised.
• -r: resolution, a resolution of at least 0.1 Å and -p option is required to get values for publishing Note: The radii used in the calculation are currently coming from the CSD website:
• http://www.ccdc.cam.ac.uk/products/csd/radii However there are several ways how the radii can be changed, one of which is to provide a file name with radii ([element radius] a line format). The other is to load the radii from the same kind of the file using >>load radii vdw command.