dc.contributor.author | Lu, Hsiao-ming | |
dc.contributor.author | Hardy, J. | |
dc.date.accessioned | 2017-04-25T19:22:14Z | |
dc.date.issued | 1992 | |
dc.identifier | Quick submit: 2017-03-22T16:01:27-0400 | |
dc.identifier.citation | Lu, 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.issn | 0163-1829 | en_US |
dc.identifier.uri | http://nrs.harvard.edu/urn-3:HUL.InstRepos:32416116 | |
dc.description.abstract | Structural 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.iso | en_US | en_US |
dc.publisher | American Physical Society (APS) | en_US |
dc.relation.isversionof | 10.1103/physrevb.45.7609 | en_US |
dash.license | LAA | |
dc.title | Simulations of phase transitions in Rb2ZnCl4 | en_US |
dc.type | Journal Article | en_US |
dc.date.updated | 2017-03-22T20:01:27Z | |
dc.description.version | Version of Record | en_US |
dc.relation.journal | Physical Review B | en_US |
dash.depositing.author | Lu, Hsiao-ming | |
dc.date.available | 1992 | |
dc.date.available | 2017-04-25T19:22:14Z | |
dc.identifier.doi | 10.1103/physrevb.45.7609 | * |
dash.contributor.affiliated | Lu, Hsiao-Ming | |