Firefly and PC GAMESS-related discussion club

Learn how to ask questions correctly

What criterion of comparison of structures by means of Chemcraft?,


Dear clubmen FireFly!
  I executed in a gas phase for a molecule from
40 atoms and have received all positive frequencies (structure 1).
Then has executed and has received geometry a bit
another (structure 2).
   Then under instructions A. Granovsky and Sanya I have compared
both structures by means of Chemcraft and have received such results:

                      RMSD, Ang
                   All atoms                     0.076
                   By each kind of atoms:      H 0.0716
                                               C 0.0448
                                               O 0.0980
                                               N 0.0479

Whether it is necessary to carry out at such distinctions calculation
hessian for structure 2?
First, it will be long and expensively. Secondly, under the remark from
Sanya, "it is not recommended to calculate hessians in PCM because of
numerical instabilities and some other computational problems."

I ask the help in my problem.

With regards,

[ Previous ] [ Next ] [ Index ]           Sat Jan 22 '11 1:02am
[ Reply ] [ Edit ] [ Delete ]           This message read 1185 times