I agree completely with Tom, and would only add that the DelPhi ESP map format (*.phi file) that Chimera reads is from the academic version of DelPhi obtained from the Honig group, as mentioned here:

<http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/filetypes.html#esp>

I don't know if this is still true, but at least at some point in the past there was a commercial version of DelPhi that worked with the Insight program, and that may create a different format of ESP map that Chimera does not read.

Best,

Elaine

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Elaine C. Meng, Ph.D.

UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab

Department of Pharmaceutical Chemistry

University of California, San Francisco

On Sep 24, 2010, at 6:13 PM, Tom Goddard wrote:

Hi Nitesh,
I don't use DelPhi so I don't know if your function calls are right. I am sure that the file you sent has totally different record sizes than those documented for the *.phi file format. Could your file actually be a surface file rather than an electrostatic grid? These questions about whether you are using DelPhi correctly or why the record structure of your *.phi file does not match the documented file format are best answered by DelPhi experts rather than the Chimera developers. Let me know what you find out.
Tom