Evaluation of the crystal field-closure-ligand polarization interference term for the vibronic intensities of centrosymmetric coordination compounds

Abstract

A reexamination of the relative phases of the crystal field-closure and ligand polarization contributions to the intensities of individual vibronic origins shows that the interference term is appreciable and positive for the v3, v 4 and v 6 vibronic origins of the 4A2g*-*4T2g transition of the MnF62-ion. We had previously reported that this term was identically zero for v 6 but this error arose from the use of an inconsistent choice of phases in the v 6 symmetry coordinate. A corrected table of computed dipole strengths and relative vibronic intensities is given which is in excellent agreement with experiment.

Vibronic intensities in the electronic spectra of transition metal ions

“…The L matrices were taken from [1], results for the other force fields included in [1][2][3] are available from the authors. For the crystal field contribution a question arises over the magnitude of the effective charge q on the ligand.…”

“…As in [3] we shall use the closure approximation for evaluation of the crystal field term since not all of the integrals required for the single p-state approximation are available. This gives for the 4A2g--~ 4Tag transition in an octahedral complex.…”

“…In recent papers [1][2][3] we have evaluated the relative vibronic intensity distribution for the vibronic origins of the 4A2g-* 4T2g transition of the MnF62-ion due to the v3(tlu), v4(tlu ) and v6(t2u ) vibrational modes. Both crystal field and ligand polarization contributions and the cross term between them were considered for a variety of vibrational force fields and d-electron radial functions.…”