Determination of Heisenberg Exchange Coupling Constants in Clusters with Magnetic Sites: A Local Spin Approach

DIEGO R. ALCOBA; ALICIA TORRE; LUIS LAIN; OFELIA B. OÑA; JOSEP M. OLIVA

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY

JOHN WILEY & SONS INC

Lugar: New York; Año: 2014 vol. 114 p. 952 - 958

0020-7608

This work studies the ability of the two-center local spin quantities, provided by the partitioning of the expectation value of the spin-squared operator corresponding to N-electron systems, for determining spin-exchange coupling constants within the Heisenberg spin Hamiltonian model. The spin exchange parameters, which characterize this Hamiltonian for a determined system, have been evaluated in the HeH2 aggregate and in several Hn clusters (n= 2, 3, 4) with different geometrical arrangements, using internuclear distances larger than the equilibrium ones (beyond the bonding regions). The results found have been analyzed and compared with those arising from other approaches, showing the feasibility of our methodology.