Dear, I'm Jayaraman T pursuing PhD here in Pusan National University. Since we are interested to calculate the interhelical angle and axes for a set of proteins, we found Chimera is really helpful for getting us the results. And i would like to do certain analysis on the basis of these interhelical angles, so i kindly request you to provide me the source code and other requirements for calculating the angle between helices. It would be grateful to you and please help me out at your earliest convenience. Thanks -- Regards Jram | 201493155 PhD Student Bio molecular Engineering Lab School of Chemical Engineering Pusan National University. 30 Jangjeon-dong, Geumjeong-gu, Busan, South Korea - 609-735. +8210 9906 3680 jram@pusan.ac.kr