There's a package called CAST by Jie Liang available at http://sunrise.cbs.umn.edu/cast that will do that. Hiroki Jonathan Ho (ysh5a at avery.med.Virginia.EDU) wrote: : Hello, : I wanted to calculate the volume of a gorge in a protein, is : there anyway I can do that in O, ccp4 programs or any other : programs? : Thanks. : -- : Yew Seng Jonathan Ho