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AMBER Archive (2009)Subject: [AMBER] dihedral force calculation
From: Germain Vallverdu (germain.vallverdu_at_lcp.u-psud.fr)
Dear amber users
I am trying to understand the cartesian forces calculations in the case
I supposed that the following is used
f = - d E(phi) / d r = 1/sin phi * dE(phi)/d phi * d cos phi / d r
and then with special stuff if sin phi tends to zero we, get the
f = - df * d cos phi / d r (line 344 in dihedrals.f90 in pmemd in
I do not understand the calculation of the cos phi derivative. But maybe
I juste would like to know if my previous equation is right. Mainly is
Thanks for your help.
germain
-- Germain Vallverdu Doctorant Laboratoire de Chimie Physique germain.vallverdu_at_lcp.u-psud.fr 01 69 15 30 38
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