1205.1146 (S. V. Streltsov et al.)

Theoretical prediction of Jahn-Teller distortions and orbital ordering
in Cs2CuCl2Br2    [PDF]

S. V. Streltsov, D. I. Khomskii

With the use of the density function calculations we show that the actual crystal structure of Cs$_2$CuCl$_2$Br$_2$ should contain elongated in the $ab-$plane CuCl$_4$Br$_2$ octahedra, in contrast to the experimentally observed compression in $c-$direction. We also predict that the spins on Cu$^{2+}$ ions should be ferromagnetically ordered in $ab-$plane, while the exchange interaction along $c-$direction is small and its sign is uncertain.

View original: http://arxiv.org/abs/1205.1146