CHEMtalks: Associate Professor Høgni Weihe

Høgni Weihe

Zoom link here.

From Spectroscopic and Thermodynamic Data via Heisenberg Exchange Operators to Structural Information - and vice versa."

Interpretation of magnetic susceptibilities obtained from clusters containing a large number of paramagnetic ions involves diagonalization of very large Heisenberg operator energy matrices. A simple approach to extract essential features of eigenvalue distributions of large and essentially non-diagonalizable Heisenberg exchange energy matrices is presented. This method facilitates the interpretation of magnetic susceptibility data from large spin systems. For small spin systems, it is shown that the Q dependence of certain magnetic excitations provide direct information about which ions in the lattice are correlated via the Heisenberg exchange operator.