Electronic structure and magnetic anisotropy of the [Co_4(hmp)_4(CH_3OH)_4Cl_4] molecule
arXiv:cond-mat/0211221 · doi:10.1016/S0009-2614(02)00824-2
Abstract
Accurate density-functional based calculations have been performed on the Co_4(hmp)_4(CH_3OH)_4Cl_4 molecular magnet where hmp is deprotonated hydroxymethyl pyridine. In addition to the experimentally observed staggered geometry, we identify two isomers, referred to as eclipsed and half-staggered/half-eclipsed, that are reasonably low in energy. Our calculations show that the magnetic anisotropy is strongly dependent on the pyridine-pyridine separation and that the three structures exhibit easy axis, easy plane and triaxial behavior. Other effects such as partial reprotonation of the hmp is considered.
6 pages, 4 figures