Dear all Is it possible to put restraint on only peptide bonds? I would like to put restraint on O-N bond lengths, Ca-O-N angles, and O=O-N angles. Could you teach me how to do it, if possible? Best regards ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Masaki UNNO, Ph.D. Frotier Research Center for Applied Atomic Sciences, Ibaraki University Ibaraki Quantum Beam Research Center 162-1 Tokai, Shirakata, Naka, Ibaraki 319-1106, Japan Tel: 029-352-3239, Fax: 029-287-7872 E-mail: [log in to unmask] HP: http://www.fas.ibaraki.ac.jp/?page_id=961 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~