Indeed, the first thing is to distort along the 400i mode, and
reoptimize. Normally that should go to the new structure where it is
gone.
if not, then depending on the software you use you might be able to do
a scan along the normal mode, which recomputes the frequency
value.
Often this shows that the imaginary value is spurious and in
reality it is positive.
If you cannot do that, then try computing the
frequency with larger grid.
Sent
to CCL by: "SUMANGLA ARORA" [arorasumangla*_*
gmail.com]
Dear
All,
I am getting three imaginary modes in a transition state viz., i1300,
i400,
i50. Out of them, i1300 is the correct one which has the vibrational
mode we
were expecting. How can we eliminate the other imaginary modes?. I
have tried
to eradicate the i400 imaginary mode by taking the geometry on
both ends of the
vibrational mode (i400), but this is not
working.
Thanks
Marcel Swart
ICREA Research Professor at
University of Girona
Director of Institut de
Química Computacional i Catàlisi
Univ. Girona, Campus Montilivi
(Ciències)
c/
M.A. Capmany 69
17003 Girona, Spain
vCard