Getting freq in g98 solvated structures
I am trying to get with g98 a vibrational analysis of some solvated
structures, but I have a lot of problems.
Following I will show the methodology I have been using.
1) Optimization using the continuum model dpcm
#P SCRF=(DPCM,solvent=1) Opt HF/6-31+G* SCF=(direct,tight)
OK, I got the minimised structures
2) Vibrational analysis
#P freq Geom=Allcheckpoint Guess=read HF/6-31+G*
In this analysis I got always one or two negative frequencies, and
finally the system starts an optimization and it ends with a non
converged structure message:
Item Value Threshold Converged?
Maximum Force 0.036807 0.000450 NO
RMS Force 0.010077 0.000300 NO
Maximum Displacement 0.159966 0.001800 NO
RMS Displacement 0.051859 0.001200 NO
Predicted change in Energy=-7.193508D-03
Does anybody know what is the problem?
Thanks in advance
Juan Frau Munar
Universitat Illes Balears
Departament de Quimica
Palma de Mallorca - 07071
email: juan (- at -) originqf.uib.es
fax: 971 - 173426
telf: 971 - 173254