Subject: MNDO Curvilinear step convergence

From: "Daniel L. Bhering" <[email-masked]>
Date: Thu, 7 Mar 2002 11:12:00 -0300

Dear Friends,
I have some problems with semiempirical calculations (MNDO) under Gaussian 98 of system with 170 atoms (Si,Al, O and H). Some constrains are used in order to fix the geometry like in zeolite cell (the H atoms are frozen using addredundant option).
The message error is: 
   
Curvilinear step not converged.
Error imposing constraints
Error termination via Lnk1e in d:\quimica\g98w\l103.exe.
Job cpu time: 0 days 0 hours 10 minutes 5.0 seconds.
File lengths (MBytes): RWF= 33 Int= 0 D2E= 0 Chk= 36 Scr= 1

I would like to know if it is possible to change the Curvilinear step convergence or increase its maximum step.

Thanks in advance,

Daniel L. Bhering

The end of the file is:

  GradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGrad
  Berny optimization.
  Use GDIIS/GDPIS optimizer.
  Internal Forces: Max 0.066574391 RMS 0.005245074
  Search for a local minimum.
  Step number 2 out of a maximum of 927
  All quantities printed in internal units (Hartrees-Bohrs-Radians)
  Swaping is turned off.
  2 1 -0.1092465E-02 0.2080001E-02 0.5252233 
  Update second derivatives using information from points 1 2
  Trust test= 1.72D+00 RLast= 1.33D-01 DXMaxT set to 3.98D-01
  lowest eigenvalue of the Hessian is 0.1457 .
  RFO step: Lambda= 2.16960443D-04.
  DIIS coeff's: 5.10805 -4.10805
  Cosine: 0.998 > 0.866
  Length: 1.064
  GDIIS step was calculated using 2 of the last 2 vectors.
  Iteration 1 RMS(Cart)= 0.05470182 RMS(Int)= 0.00156511
  Iteration 2 RMS(Cart)= 0.00463266 RMS(Int)= 0.00054886
  Iteration 3 RMS(Cart)= 0.00001324 RMS(Int)= 0.00054881
  .
  .
  .

  Iteration 97 RMS(Cart)= 0.00000239 RMS(Int)= 0.00016218
  Iteration 98 RMS(Cart)= 0.00000234 RMS(Int)= 0.00016243
  Iteration 99 RMS(Cart)= 0.00000229 RMS(Int)= 0.00016268
  Iteration100 RMS(Cart)= 0.00000224 RMS(Int)= 0.00016293
  Curvilinear step not converged.
  Error imposing constraints
  Error termination via Lnk1e in d:\quimica\g98w\l103.exe.
  Job cpu time: 0 days 0 hours 10 minutes 5.0 seconds.
  File lengths (MBytes): RWF= 33 Int= 0 D2E= 0 Chk= 36 Scr= 1