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The Hamiltonian of the V$_{15}$ Spin System from first-principles Density-Functional Calculations

Jens Kortus·C. Stephen Hellberg·Mark R. Pederson
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Abstract

We report first-principles all-electron density-functional based studies of the electronic structure, magnetic ordering and anisotropy for the V$_{15}$ molecular magnet. From these calculations, we determine a Heisenberg Hamiltonian with four antiferromagnetic and one {\em ferromagnetic} coupling. We perform direct diagonalization to determine the temperature dependence of the susceptibility. This Hamiltonian reproduces the experimentally observed spin $S$=1/2 ground state and low-lying $S$=3/2 excited state. A small anisotropy term is necessary to account for the temperature independent part of the magnetization curve.

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Jens Kortus, C. Stephen Hellberg, Mark R. Pederson. 2001-03-06. The Hamiltonian of the V$_{15}$ Spin System from first-principles Density-Functional Calculations. https://doi.org/10.1103/physrevlett.86.3400

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