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dc.contributor.authorLu, Hsiao-ming
dc.contributor.authorHardy, J.
dc.date.accessioned2017-04-25T19:22:14Z
dc.date.issued1992
dc.identifierQuick submit: 2017-03-22T16:01:27-0400
dc.identifier.citationLu, H., and J. Hardy. 1992. “Simulations of Phase Transitions in Rb2ZnCl4.” Physical Review B 45 (14) (April): 7609–7620. doi:10.1103/physrevb.45.7609.en_US
dc.identifier.issn0163-1829en_US
dc.identifier.urihttp://nrs.harvard.edu/urn-3:HUL.InstRepos:32416116
dc.description.abstractStructural relaxations, molecular-dynamics simulations, and lattice-dynamics calculations were performed to study the phase transitions in Rb2ZnCl4, using intermolecular and intramolecular potentials generated from ab initio quantum-chemistry calculations for the whole molecular ion ZnCl42-. Compared with an earlier treatment of the system by a polarizable-ion model, the present approach emphasizes the static effect of the electron covalency within the molecular ions that affects strongly both the intermolecular and intramolecular interactions. The calculations gave a close agreement with experiment on the static structures of the Pnam and the Pna21 phases and the transition temperature from the former to the latter. For the lower-temperature, monoclinic phase of Rb2ZnCl4, the detailed structure of which is unknown, our simulations predict a structure with C1c1 space-group symmetry, which doubles the Pna21 structure along both the b and c axes and thus has 48 formula units per unit cell. The lattice-dynamics calculations for the Pna21 structure clearly revealed the lattice instability responsible for the Pna21-monoclinic transition and provided a more convincing explanation of a previous Raman measurement. We have shown that the potential-energy surface in Rb2ZnCl4 pertinent to the phase transitions contains a double-well structure, very similar to that of K2SeO4, except that the double well is much deeper, causing the much more severe disordering in the Pnam structure of Rb2ZnCl4 observed experimentally.en_US
dc.language.isoen_USen_US
dc.publisherAmerican Physical Society (APS)en_US
dc.relation.isversionof10.1103/physrevb.45.7609en_US
dash.licenseLAA
dc.titleSimulations of phase transitions in Rb2ZnCl4en_US
dc.typeJournal Articleen_US
dc.date.updated2017-03-22T20:01:27Z
dc.description.versionVersion of Recorden_US
dc.relation.journalPhysical Review Ben_US
dash.depositing.authorLu, Hsiao-ming
dc.date.available1992
dc.date.available2017-04-25T19:22:14Z
dc.identifier.doi10.1103/physrevb.45.7609*
dash.contributor.affiliatedLu, Hsiao-Ming


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