This plugin reads binary potential maps in the format used by DelPhi and Grasp. More information on this format can be found at http://honiglab.cpmc.columbia.edu/grasp/grasp_contents.html#A.2 and http://trantor.bioc.columbia.edu/delphi/doc/file_format.html. To read the "formatted ASCII" files created by format_phi, use the phiplugin.
This plugin is used only to read files. VMD does not currently support writing this file type.
It is assumed that the density values of all files are arranged in a cubic grid. This plugin is not limited to 65x65x65 grid points as earlier versions of the file format are.
Since PHI maps do not explicitly state the angles of the basis vectors, it is assumed that they are orthogonal.