CCL: force calculation on mopac



 Sent to CCL by: John McKelvey [jmmckel---attglobal.net]
 
In earlier versions of MOPAc such as '93 or '97 on could choose EF for the optimizer and also add GNORM=0.0001 LET DDMIN=0 SCFCRT=1.d-10 ...
 Regards,
 John McKelvey
 Gon alo Justino goncalo.justino * zmail.pt wrote:
 
 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>