Issue 7, 2007

Database guided conformation selection in crystal structure prediction of alanine

Abstract

Crystal structure prediction calculations have been performed for the α-amino acid alanine with the intention of developing reliable computational methods for flexible molecules and, specifically, to study the crystal packing of the more flexible amino acids. For the α-amino acids, the density functional theory geometry optimised conformations of the isolated molecules are considerably different, in both geometry and form, to what is observed in the crystal structures. The molecules take the zwitterionic form in the observed crystals, but are nonionised for the isolated molecules. The quantum mechanically optimised structure of the isolated molecule is therefore a poor starting point for computationally generating putative crystal structures. We show that, by limiting the conformations of alanine to the torsion angle distributions in the observed crystal structures of similar molecules in the Cambridge Structural Database, sets of likely crystal structures can be generated, with the lowest energy racemic and enantiopure crystal structures corresponding to the experimentally observed crystal structures.

Graphical abstract: Database guided conformation selection in crystal structure prediction of alanine

Article information

Article type
Paper
Submitted
12 Feb 2007
Accepted
22 Mar 2007
First published
04 Apr 2007

CrystEngComm, 2007,9, 595-602

Database guided conformation selection in crystal structure prediction of alanine

T. G. Cooper, W. Jones, W. D. S. Motherwell and G. M. Day, CrystEngComm, 2007, 9, 595 DOI: 10.1039/B702136D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements