2007/10/02 by G. Baldacchini, R. M. Montereali, Baldacchini, G. +15
Chemistry · Materials Science · Physics and Astronomy · #Advanced NMR Techniques and Applications #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Molecular Spectroscopy and Structure #Solid-state spectroscopy and crystallography #physics.chem-ph
paper · pdf · doi:10.48550/arxiv.0710.0650
14 pages including 2 tables and 3(4) figures, all pdf format
arxiv created 2007/10/02 · openalex publication_date 2007/10/02 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Because of its inherent 2-D character, the eigenvalue equation for the hindered rotation around a normal cation site of an off-center impurity nearest-neighboring an F center is the well-known Mathieu equation. We present an overview of literature data on Mathieu's periodic functions providing exact solutions to the Li+ reorientational problem. We compare them with bottom-well approximating solutions by harmonic-oscillator functions at an effective vibrational frequency renormalized by both first- and third- order electron-mode coupling. We finally discuss the in-plane inversion polarizability of an off-center impurity assumed to form a dipole-dipole coupling with a nearby F center.