Hi Nikolay, Try the Amber web site and/or manuals. Google and Pubmed may also be useful. <http://ambermd.org/> There is some information in the Add Charge manual page of the Chimera User's Guide, <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/addcharge/addcharge...> ... but be aware that minimization in Chimera always uses ff99 for all parameters other than the charges, as mentioned here: <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/minimize/minimize.h...> ... because that is what the MMTK package used by Chimera provides. Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On May 12, 2012, at 4:08 PM, Nikolay Igorovich Rodionov wrote:

Hi all, Could someone point in the direction of some good documentation on ff99SB, how it functions, and what calculations it performs? Thank you, Nikolay Rodionov