From owner-chemistry #at# ccl.net Sat Mar  4 23:30:00 2006
From: "Tony Yuan TYuan=cambridgesoft.com" <owner-chemistry[A]server.ccl.net>
To: CCL
Subject: CCL: force calculation on mopac
Message-Id: <-31112-060304174951-12345-+e1Q5mSn6t/oBLctG/BMpQ[A]server.ccl.net>
X-Original-From: "Tony Yuan" <TYuan%x%cambridgesoft.com>
Date: Sat, 4 Mar 2006 21:21:06 -0500


Sent to CCL by: "Tony Yuan" [TYuan(-)cambridgesoft.com]

See http://forum.chemih.com/forum/view.asp?aid=664&cid1

[edited by jkl*ccl.net to remove winmail.dat]

-----Original Message-----
From: Gon alo Justino goncalo.justino * zmail.pt 
Sent: Sat 3/4/2006 6:35 PM
To: Tony Yuan
Subject: CCL: force calculation on mopac

Sent to CCL by: "Gon  alo  Justino" [goncalo.justino*zmail.pt]
Dear all,

I recently upgraded to mopac 2002 built in ChemDraw for Windows. I'm 
trying to get a force calculation running but I'm stuck at this:

 - when I use AM1 GNORM=0.01 everything is ok, i get a nice output file;
 - when I use AM1 FORCE I get back  ** GRADIENT IS TOO LARGE TO ALLOW 
FORCE MATRIX TO BE CALCULATED, (LIMIT=10) ** EITHER ADD 'LET' OR 
REDUCE GRADIENT   USING 'TS' OR OTHER GEOMETRY OPTIMIZER~
 - if I use AM1 FORCE TS, or AM1 FORCE LBFGS, I get back MORE THAN ONE 
GEOMETRY OPTION HAS BEEN SPECIFIED; CONFLICT MUST BE RESOLVED BEFORE JOB 
WILL RUN.

This happens for any molecule. Is this my incompetence, software 
conflict or simple mis-installation?

Any suggestion is welcome,

Gonalo Justino
goncalo.justino[a]zmail.pt