From: Stefan Franzen (
Date: Sun May 02 2010 - 16:48:20 CDT

*I used the NAMD tutorial and the it would not accept the default parameters
for PME (1-3-box)
Looking in the manual I read:

PMEGridSizeX * [image: $<$] number of grid points in x dimension [image:
*Acceptable Values: * positive integer
*Description: * The grid size partially determines the accuracy and
efficiency of PME. For speed, PMEGridSizeX should have only small integer
factors (2, 3 and 5).

It seems to me that the following must be true:

(grid spacing) x (number of grid points in given dimension) > box length

That makes sense and it is what I determined empirically.

Please clarify.

Stefan Franzen
Professor of Chemistry
North Carolina State University
Raleigh, NC 27695
Phone: 919-515-8915