Honl-London factors for multiplet transitions in Hund's case a or b

Honl-London factors are the factors that give the dependence of spectroscopic line intensities on the rotational quantum numbers. Recently it has been shown that most tabulations of Honl-London factors for singlet-singlet transitions do not allow for the special cases of Pi-Sigma and Sigma-Pi transitions, where a consideration of the parity symmetrisation shows that an extra factor of 2 is required. The present paper extends these considerations to multiplet transitions, in either pure Hund's case a or pure Hund's case b. (C) 2008 Elsevier Inc. All rights reserved.