Dear all,

in my calculated frequencies for a uranium containing closed-shell
molecule,
I get one imaginary frequency which is doubly degenerate due to
symmetry.
Now, while it is perfectly possible that these are 'real' because the
molecule
would have a lower symmetry in its ground state, I am still wondering
whether this is, in fact, noise, given that the calculated frequencies
are only
13.0i cm^-1.
   Thus, my questions are: What is the accuracy of the finite-difference
ADF
frequencies for very floppy modes? Can calculated frequencies of 13i
cm^-1
still be noise? Any further comments on the subject?
   I am using scalar ZORA, INTEGRATION 8, default values for
'frequencies',
PW91, frozen core ZORA basis V, cartesian coordinates, D5 symmetry.

Thank you very much!

Best regards, Georg

--
Dr. Georg Schreckenbach          phone: +44-1925-603849
CLRC Daresbury Laboratory      FAX: +44-1925-603634
Daresbury, Warrington, Cheshire, WA4 4AD, UK
h.g.schreckenbach@dl.ac.uk   http://www.geocities.com/gschreckenbach/