CCL:G: Hessian Matrix in Internal Coordinates

 Sent to CCL by: Andrea Coletta [andrea_coletta,,]
Hi, i'm trying to obtain the Hessian Matrix output in Internal Coordinates, from a B3LYP Optimization job with Gaussian03.C02.
 My route section is:
 #P B3LYP/6-31G* OPT=CalcAll SCRF=CPCM
if I use this with a small molecule (e.g Water), in the log file I find something like:
 (Enter /apps/GEN03.C02/g03/l103.exe)
 Berny optimization.
 Internal  Forces:  Max     0.000010959 RMS     0.000006781
 Search for a local minimum.
 Step number   4 out of a maximum of  20
 All quantities printed in internal units (Hartrees-Bohrs-Radians)
 Second derivative matrix not updated -- analytic derivatives used.
 Trust test= 1.00D+00 RLast= 3.53D-03 DXMaxT set to 4.24D-01
 The second derivative matrix:
                          R1        R2        A1
           R1           0.46509
           R2          -0.00302   0.46509
           A1           0.02978   0.02978   0.16989
     Eigenvalues ---    0.16394   0.46802   0.46812
 RFO step:  Lambda= 0.00000000D+00.
 and this is exactly what I want!
 It works also with an HF Opt test-job I did with Glycine:
 #P HF/3-21G OPT=(ModRedundant,CalcAll) SCRF=pcm
 Force constants in Cartesian coordinates:
                1             2             3             4             5
      1  0.809587D+00
      2  0.000000D+00  0.790299D+00
      3  0.137405D-01  0.000000D+00  0.642144D+00
      4 -0.114527D+00  0.000000D+00 -0.475510D-02  0.644272D+00
5 0.000000D+00 -0.110951D+00 0.000000D+00 0.000000D+00 0.621385D+00 6 0.118871D-01 0.000000D+00 -0.243725D+00 -0.379120D-02 0.000000D+00
 Force constants in internal coordinates:
                1             2             3             4             5
      1  0.426378D+00
      2  0.122242D-01  0.472234D+00
      3  0.115444D-01  0.547739D-02  0.471563D+00
      4  0.115444D-01  0.547739D-02  0.574356D-02  0.471563D+00
5 0.138575D-01 -0.102523D-02 -0.441368D-02 -0.441368D-02 0.404944D+00 6 0.737045D-02 0.195704D-03 0.204429D-03 -0.726729D-03 0.548064D-02
This is very good... the only difference is that it does'nt specify the internal coordinate, and it wrote the Matrix just before enthering l103.exe... rather than just after entering, like in the Water calculation...
When I try with another molecule a little greater (33 Atoms) it does'nt work!!, It does'nt print in the log the Hessian matrix, and in the fchk I find only the Hessian Matrix in Cartesian coordinates...
I use use the same Route section, and i've tried a lot of other combinations but nothing's working!
 #P B3LYP/6-31G* OPT=CalcAll SCRF=CPCM
 #P B3LYP/6-31G* OPT=(Redundant,CalcAll) SCRF=CPCM
 #P B3LYP/6-31G* OPT=(ModRedundant,CalcAll) SCRF=CPCM
 #P B3LYP/6-31G* OPT=CalcFC
 etc. etc.
Maybe the problem is that my system has too many internal degree of freedom (96)?
 Any Suggestions?
 Please Help me!! :-(
 Andrea Coletta
 Post-Grad. Student
 University of "Tor Vergata"
 Rome - Italy