TY - JOUR

T1 - Theoretical study of structural phase transition in a RbMnCl3 crystal by the Kim-Gordon method

AU - Smirnov, M. B.

AU - Kazimirov, V. Yu

N1 - Funding Information: ACKNOWLEDGMENTS This study was supported by INTAS, project no. 97-10177, and the Russian Foundation for Basic Research, project no. 00-03-33040. The authors are grateful to I.I. Tupitsyn for the program for quantum-chemical computations by the Hartree–Fock method. Copyright: Copyright 2008 Elsevier B.V., All rights reserved.

PY - 2003/5

Y1 - 2003/5

N2 - Symmetry analysis of the low-temperature phase of RbMnCl3 crystals with the monoclinic axis perpendicular to the sixfold axis of the high-temperature phase showed that its space group is either C2h3 or C2h6. The distribution of normal vibrations over the irreducible representations of the high-temperature phase is refined, and the symmetry relationships for normal vibrations of all possible low-temperature phases are tabulated. The model of the potential function of the crystal is obtained by the nonempirical Kim-Gordon method. This model allows one to establish the existence of the saddle point of the potential surface and several harmonically unstable modes corresponding to correlated rotations of rigid MnCl6 and Mn2Cl9 polyhedra. The absolute energy minimum is determined by deforming the lattice along the eigenvector of the E1g mode within the sp. gr. C2h6.

AB - Symmetry analysis of the low-temperature phase of RbMnCl3 crystals with the monoclinic axis perpendicular to the sixfold axis of the high-temperature phase showed that its space group is either C2h3 or C2h6. The distribution of normal vibrations over the irreducible representations of the high-temperature phase is refined, and the symmetry relationships for normal vibrations of all possible low-temperature phases are tabulated. The model of the potential function of the crystal is obtained by the nonempirical Kim-Gordon method. This model allows one to establish the existence of the saddle point of the potential surface and several harmonically unstable modes corresponding to correlated rotations of rigid MnCl6 and Mn2Cl9 polyhedra. The absolute energy minimum is determined by deforming the lattice along the eigenvector of the E1g mode within the sp. gr. C2h6.

UR - http://www.scopus.com/inward/record.url?scp=0037960819&partnerID=8YFLogxK

U2 - 10.1134/1.1578128

DO - 10.1134/1.1578128

M3 - Article

AN - SCOPUS:0037960819

VL - 48

SP - 435

EP - 442

JO - Crystallography Reports

JF - Crystallography Reports

SN - 1063-7745

IS - 3

ER -