Subject: parameters for NiO and CoO

From: <[email-masked]>
Date: Wed, 27 Sep 1995 08:09:50 +0930

Hi,
    A student and I have been trying to do a molecular modelling
and atomic scale imaging project on NiO and CoO. This is proving to
be extremely difficult for two reasons

(a) we can't get any single crystals of these materials

(b) we have been using ZINDO to do the molecular modelling part
    of the study and the results we have been getting are 
    very odd. We have also tried the force field methodology MM+ 
    but the resulting bond lengths are far to short, about 1.8A as
    compared to 2.1 in a NiO crystal.

I know that atomic charges do not necessarily have a lot of meaning 
but the ZINDO methodology has given charges up to +6!!

Two pleas for help

- single crystals?

- parameters for Ni or Co, these can be force field, semi-empirical,
  or ab-initio - I don't mind.

At about this stage we are willing to try anything so any suggestions
will be greatly appreciated!

Thanks very much

Andy.