PASCal: a principal axis strain calculator for thermal expansion and compressibility determination

Cliffe, Matthew J.; Goodwin, Andrew L.

Abstract

This article describes a web-based tool (PASCal; principal axis strain calculator; http://pascal.chem.ox.ac.uk) designed to simplify the determination of principal coefficients of thermal expansion and compressibilities from variable-temperature and variable-pressure lattice parameter data. In a series of three case studies, PASCal is used to reanalyse previously published lattice parameter data and show that additional scientific insight is obtainable in each case. First, the two-dimensional metal–organic framework [Cu2(OH)(C8H3O7S)(H2O)]·2H2O is found to exhibit the strongest area negative thermal expansion (NTE) effect yet observed; second, the widely used explosive HMX exhibits much stronger mechanical anisotropy than had previously been anticipated, including uniaxial NTE driven by thermal changes in molecular conformation; and third, the high-pressure form of the mineral malayaite is shown to exhibit a strong negative linear compressibility effect that arises from correlated tilting of SnO6 and SiO4 coordination polyhedra.

Citation

Cliffe, M. J., & Goodwin, A. L. (2012). PASCal: a principal axis strain calculator for thermal expansion and compressibility determination. Journal of Applied Crystallography, 45(6), 1321-1329. https://doi.org/10.1107/s0021889812043026

• Journal Article Type: Article
• Acceptance Date: Oct 15, 2012
• Online Publication Date: Nov 15, 2012
• Publication Date: Dec 1, 2012
• Deposit Date: Dec 20, 2018
• Journal: Journal of Applied Crystallography
• Print ISSN: 0021-8898
• Electronic ISSN: 1600-5767
• Publisher: International Union of Crystallography
• Peer Reviewed: Peer Reviewed
• Volume: 45
• Issue: 6
• Pages: 1321-1329
• DOI: https://doi.org/10.1107/s0021889812043026
• Keywords: thermal expansion; compressibility; PASCal; computer programs
• Public URL: https://nottingham-repository.worktribe.com/output/1430688
• Publisher URL: http://scripts.iucr.org/cgi-bin/paper?S0021889812043026