On the origin independence of the Verdet tensor

CAPUTO M.C.; CORIANI S.; PELLONI S.; LAZZERETTI P.

MOLECULAR PHYSICS

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2013 p. 1 - 9

0026-8976

The condition for invariance under a translation of the coordinate system of the Verdet tensor and the Verdet constant,calculated via quantum chemical methods using gaugeless basis sets, is expressed by a vanishing sum rule involving athird-rank polar tensor. The sum rule is, in principle, satisfied only in the ideal case of optimal variational electronicwavefunctions. In general, it is not fulfilled in non-variational calculations and variational calculations allowing for thealgebraic approximation, but it can be satisfied for reasons of molecular symmetry. Group-theoretical procedures have beenused to determine (i) the total number of non-vanishing components and (ii) the unique components of both the polar tensorappearing in the sum rule and the axial Verdet tensor, for a series of symmetry groups. Test calculations at the random-phaseapproximation level of accuracy for water, hydrogen peroxide and ammonia molecules, using basis sets of increasing quality,show a smooth convergence to zero of the sum rule. Verdet tensor components calculated for the same molecules convergeto limit values, estimated via large basis sets of gaugeless Gaussian functions and London orbitals.