Substitutional and orientational disorder in organic crystals: a symmetry-adapted ensemble model

Habgood, M., Grau-Crespo, R. ORCID: https://orcid.org/0000-0001-8845-1719 and Price, S.L. (2011) Substitutional and orientational disorder in organic crystals: a symmetry-adapted ensemble model. Physical Chemistry Chemical Physics, 13 (20). pp. 9590-9600. ISSN 1463-9076 doi: 10.1039/c1cp20249a

Abstract/Summary

Modelling of disorder in organic crystals is highly desirable since it would allow thermodynamic stabilities and other disorder-sensitive properties to be estimated for such systems. Two disordered organic molecular systems are modeled using a symmetry-adapted ensemble approach, in which the disordered system is treated as an ensemble of the configurations of a supercell with respect to substitution of one disorder component for another. Computation time is kept manageable by performing calculations only on the symmetrically inequivalent configurations. Calculations are presented on a substitutionally disordered system, the dichloro/dibromobenzene solid solution, and on an orientationally disordered system, eniluracil, and the resultant free energies, disorder patterns, and system properties are discussed. The results are found to be in agreement with experiment following manual removal of physically implausible configurations from ensemble averages, highlighting the dangers of a completely automated approach to organic crystal thermodynamics which ignores the barriers to equilibration once the crystal has been formed.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/36087
Item Type	Article
Refereed	Yes
Divisions	No Reading authors. Back catalogue items Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
Publisher	Royal Society of Chemistry
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