From: Mohan maruthi sena (
Date: Wed Sep 28 2016 - 05:19:09 CDT

Dear FFTK experts,
                             I am trying to generate parameters for an
organic molecule containing 41 atoms. I have followed the FFTK
tutorial and generated charges, bond and angle parameters. I am trying
to fit dihedrals and I have not considered the dihedrals ending with
hydrogen atoms (except polar hydrogens). I have fitted the dihedrals using
simulated annealing method, the fit seems reasonably good except there
is difference in minima between quantum and fitted curve. I have
tried many ways changing various k and delta values but failed to get
the minima coinciding with QM part. Could you please provide some
insights regarding the shift in minima. Please have a look at the
plots (links provided below) containing normal and enlarged views of

Thanks and Regards,
Mohan Maruthi,
Ph.D. student,