Re: CCL:Crystal structure vs geometry optimised structure

Dear Noel

On Wed, 23 Jul 2003 noel.oboyle2[at]mail.dcu.ie wrote:

> Hello CCLers,
> I intend to carry out DFT calculations on inorganic complexes. In some cases
> I have crystal structures available.
>
> Is it better to use crystal structures as a starting point for energy
> and frequency calculations, or to use DFT-optimised structures? (where
> the DFT-optimised structure is in excellent agreement with the crystal
> structure)

There have been some papers -- eg by Buntine at University of Adelaide
and one by my co-workers -- in which the difference between
the energies of the (optimised) gas-phase structures
and those of the crystal structures are interpreted as crystal
packing energy costs.

eg:
J. Beckmann, K. Jurkschat, M. Schürmann, D. Dakternieks, A. E. K. Lim and K. F. Lim, "Comparison of the flexibility of eight-membered tetrasiloxane and stannasiloxane rings: A crystallographic and computational study", Organometallics, 2001, 20 (24), 5125-5133 <http://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/om010620o>.

Kieran
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Dr Kieran F Lim Biol. and Chemical Sciences
(Lim Pak Kwan) Deakin University
ph: + [61] (3) 5227-2146 Geelong VIC 3217
fax: + [61] (3) 5227-1040 AUSTRALIA
mobile phone: 0438 350 259 (within Australia)
mailto:lim[at]deakin.edu.au http://www.deakin.edu.au/~lim
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