Subject: G98 Symmetry

From: "Roma Oakes" <[email-masked]>
Date: Fri, 17 May 2002 15:15:23 +0100

Dear all

I am trying to do an optimisation of a porphyrin (saddle structure). I
cannot get G98 to recognise any symmetry within the molecule, I have used
iop(2/17=1).
the start of the output file says
'This structure is nearly, but not quite of a higher symmetry.
 Consider Symm=Loose if the higher symmetry is desired.'

Does anyone have any other ideas on how to get any symmetry?

the z-matrix is
C
 C                    1     1.46489
 C                    2     1.36208  1     107.32765
 C                    3     1.46489  2     107.30074  1    -2.99998  0
 N                    4     1.32832  3     110.61997  2     3.51915  0
 C                    1     1.42742  2     125.68839  3    -167.99837  0
 H                    2     1.07684  1     127.17103  6     9.00166  0
 H                    3     1.07705  2     125.52414  1    -179.99996  0
 C                    4     1.42308  3     125.2264  2    -168.     0
 N                    9     2.48163  4     94.30135  3     158.00001  0
 C                    10    1.38065  9     28.06927  4    -159.99997  0
 C                    11    1.44489  10    105.1031  9     170.00003  0
 C                    12    1.36208  11    108.6117  10   -3.00002  0
 C                    10    1.38061  9     140.29226  4    -134.41775  0
 H                    12    1.07537  11    126.07408  10   -178.00007  0
 H                    13    1.07587  12    125.01971  11   -179.99998  0
 C                    6     3.66931  1     124.75715  2     140.00045  0
 C                    17    1.36208  6     31.57118  1    -160.00264  0
 C                    6     1.42307  1     119.33617  2     150.00126  0
 N                    19    1.38442  6     123.29996  1     17.23781  0
 C                    20    1.38459  19    112.36384  6    -170.30015  0
 H                    17    1.07623  6     156.33447  1    -146.00084  0
 H                    18    1.0741   17    125.00114  6     168.99902  0
 C                    21    2.42488  20    96.36629  19   -156.06457  0
 N                    24    1.38101  21    97.53312  20    0.       0
 C                    25    1.38927  24    107.71199  21    158.52506  0
 C                    26    1.46963  25    108.50462  24    5.18742  0
 C                    27    1.36208  26    107.50112  25   -0.15033  0
 H                    28    1.07681  27    125.43996  26   -176.66351  0
 H                    27    1.07483  26    127.21118  25   -179.72895  0
 C                    26    1.41896  25    120.43101  24    159.13754  0
 C                    24    1.41284  21    31.35919  20   -157.86525  0
 H                    20    1.0138   19    123.28002  6     12.44419  0
 H                    10    1.01444  9     97.68685  4     29.99998  0
 H                    32    1.07     24    122.75667  21   -174.52872  0
 H                    6     1.07     1     119.90482  2    -26.00198  0
 H                    9     1.07     4     120.36706  3    -29.00001  0
 H                    31    1.07     26    117.36252  25    167.3077  0

Hope someone can help

Regards

Roma