Assuming you are dealing with a "pure twist", isn't the polar rotation angle reported by lsqkab or superpose what you are looking for? On Thu, 2011-10-27 at 04:16 +0000, Debajyoti Dutta wrote: > Hi all, > > Does anybody know of any software to calculate the twist angle between > two monomers in a dimeric assembly. > > Or calculate manually. > > Thank you in advance. > > Sincerely > > Debajyoti > > > Treat yourself at a restaurant, spa, resort and much more with Rediff > Deal ho jaye!