Subject: CCL: minimum geometry and imaginary frequencies

From: Pedro Aprigliano Fernandes <PFERNANDES)at(cetem.gov.br>
Date: Tue, 17 Feb 2004 13:56:16 -0300

Dear CCLers,
I am trying to optimize and calculate the minimum geometry of a molecule in
gaussian 98. How do I know that i have found that geometry in optimization
and where do i search in the output file for imaginary frequencies?

I have included here a cutout of my output wich shows negative low
frequencies, but this is really a imaginary frequency?
I am not a member of the CCL so please reply directly to my e-mail:
pfernandes)at(cetem.gov.br
N-N= 3.997713045864D+02 E-N=-1.603506616097D+03  KE= 3.445396433384D+02
  Exact polarizability:  89.458  -0.107  39.829  -0.064   6.606 119.415
 Approx polarizability: 150.116  -0.187  50.980  -0.029   2.556 165.619
 Full mass-weighted force constant matrix:
 Low frequencies ---   -8.0171   -0.0006    0.0004    0.0005   11.6757
12.6686
 Low frequencies ---   49.6615   95.7842  104.8786
 Harmonic frequencies (cm**-1), IR intensities (KM/Mole),
 Raman scattering activities (A**4/AMU), Raman depolarization ratios,
 reduced masses (AMU), force constants (mDyne/A) and normal coordinates:
                     1                      2                      3
                    ?A                     ?A                     ?A
 Frequencies --    49.5388                95.7622               104.8667
 Red. masses --     2.5902                 1.9409                 3.9429
 Frc consts  --     0.0037                 0.0105                 0.0255
 IR Inten    --     0.0139                 0.0012                 0.4366
 Raman Activ --     0.0000                 0.0000                 0.0000
 Depolar     --     0.0000                 0.0000                 0.0000
 Atom AN      X      Y      Z        X      Y      Z        X      Y      Z
   1   6    -0.01   0.11   0.06     0.03   0.00  -0.04     0.00   0.09
0.06
   2   6     0.06   0.11   0.06    -0.02   0.00  -0.04     0.00  -0.12
0.05
   3   6     0.09   0.00   0.00    -0.04   0.00   0.00     0.00  -0.20
0.04