| Abstrakt: |
Using the spin-Hamiltonian formalism the magnetic parameters are introduced through the components of the Λ-tensor involving only the matrix elements of the angular momentum operator. The energy levels for a variety of spins are generated, and the modeling of the magnetization, the magnetic susceptibility, and the heat capacity is done. Theoretical formulae necessary for performing the energy level calculations for a multiterm system are prepared with the help of the irreducible tensor operator approach. The goal of the programming is to evaluate the entire relevant matrix element (electron repulsion, crystal field, spin–orbit interaction, orbital-Zeeman, and spin-Zeeman operators) in the basis set of free-atom terms. The modeling of the zero-field splitting is done at three levels of sophistication: (i) the differences in the crystal-field multiplets when the high-dimensional matrix in the complete space is diagonalized; (ii) the differences in the energy levels of a model subspace when the partitioning technique is applied in the first iteration; (iii) the differences in the energy levels as they are produced by the second-order perturbation theory for the spin Hamiltonian. The spin-Hamiltonian formalism offers simple formulae for the magnetic parameters (the D-factors , D-parameter, χTIP) by evaluating the matrix elements of the angular momentum operator in the basis set of the crystal-field terms. The magnetic functions for dn complexes are modeled for a wide range of crystal-field strengths. [ABSTRACT FROM AUTHOR] |
