Re: CCL:Crystal structure vs geometry optimised structure

["Roma Oakes" <r.e.oakes=at=btconnect.com>]

Hi Noel
 Before carrying out a frequency calc it is essential that you have optimised
 the geometry at the same level of theory. Therefore you can start with
 either your crystal structure or your previously optimised structure.
 Regards
 Roma
 > -----Original Message-----
 > From: Computational Chemistry List [mailto:chemistry-request=at=ccl.net]On
 > Behalf Of noel.oboyle2=at=mail.dcu.ie
 > Sent: 23 July 2003 08:28
 > To: chemistry=at=ccl.net
 > Subject: CCL:Crystal structure vs geometry optimised structure
 >
 >
 > 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)
 >
 > Thanks,
 > Noel O'Boyle
 > Han Vos Research Group,
 > Dublin City University.
 >
 >
 Roma E. Oakes
 Postgraduate Student
 School of Chemistry
 The Queen's University of Belfast
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 Tel: (+)44 (0)28 91821021
 Email: r.oakes=at=qub.ac.uk
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