INTERPRETATION OF DATA OBTAINED FROM MÖSSBAUER, ESR, SUSCEPTIBILITY, OPTICAL AND XPS MEASUREMENTS

Abstract
Molecular orbital calculations are designed to calculate the electronic and magnetic structure for molecules or clusters. With the calculated electronic structure (eigenvalues ε and eigenvectors ψ of the relevant electronic Hamiltonian) it is in principle possible to evaluate spectroscopic data from corresponding expectation values <ψ_i | ô | ψ_f>, where ψ_i represents the initial and ψ_f the final electronic state, and ô is the appropriate operator (i.e. δ([MATH]) for deriving electron and spin densities, (3pq - γ²δ_pq)/γ⁵ for electric field gradients, [MATH] for dipole moments and transitions, [MATH] for magnetic moments). Including energy spacing and Boltzmann population of electronic states in the calculation lead to temperature dependent data. Experimental data obtained from Mössbauer, ESR, susceptibility, optical and XPS measurements are related to the expectation values mentioned above. The calculational procedure will be described, and comparison of calculated and measured data will be presented.