xleap problem

From: FyD <fyd_at_u-picardie.fr>
Date: Thu 27 Jun 2002 10:20:53 +0200

Dear All,

I used "xleap" to generate "prmtop" and "prmcrd" files of an unusual
unit. I checked the generated improper FF parameters with "rdparm". It
looks like that an improper center has been selected for a CT atom type
by xleap.
See the output of rdparm just below:
B 33: 1.000 3.14 2.0 :1_at_H1 :1_at_N1 :1_at_C6 :1_at_C2
Moreover, this oop is totally wrong topologically even if CT would be a
C atom type. Indeed atom numbers 2, 1, 11 and 3 cannot make an improper

I set up the CT atom type for C6 in the OFF library. See below:
!entry.MOL.unit.atoms table str name str type int typex int resx
int flags int seq int elmnt dbl chg
 "C6" "CT" 0 1 131073 11 6 0.020900

After reading http://amber.ch.ic.ac.uk/Questions/improp.html,
each sp2 atom should be an improper center; not a CT/sp3 atom type....

What could be the problem ?

Thanks, Regards, Francois
Received on Thu Jun 27 2002 - 01:20:53 PDT
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