Subject: Help on Basis II trouble

From: Giju Thomas Kalathingal <[email-masked]>
Date: Fri, 28 Jul 2000 16:01:38 -0400 (EDT)

Hi everybody,

I have done a set of calculations on transition metal complexes
with a series of basis sets at B3LYP level using Gaussian98. These
included CEP, SDD, LANL2DZ (as avaialable with g98) and basis II as
discribed in 
'Reviews in Computational Chemistry', Vol. 8, K.B. Lipkowitz and D.B. Boyd
(Eds), VCH, New York, p. 63 - 144 (1996). 
For basis II, I have used Hay&Wadt pseudo-ECP and the corresponding
valence basis sets for transition metal. For main group elements,
6-31G(d,p) was used. 

The problem is that, of all the basis sets I used, the basis II gives
an imaginary frequency. Now I am worried about the time I spent and
the already published results using this basis sets by other people.

Here is the question. Does the mixing of ECP and all electron basis sets
in basis II make the selection incompatible? More specifically,
is the mixing in basis II is compatible?
Or, basis II is correct while all others (CEP, SDD, LANL2DZ) are wrong?

Hope you are able to help me.

Thanks,
Giju