Electronic Energy Levels and Crystal Quantum States of Tm (IV)

Abstract

To date limited agreement has been obtained between theory and experiment for 4f→4f transitions for Tm (IV) (4f¹²). It is clear from the considerations that have appeared so far in the literature that intermediate coupling is important in the case of Tm (IV). Solutions of the intermediate field equations yield ζ_4f=2700 cm^—1, F₂=450 cm^—1, and x=(ζ/F₂)=3. Experimental agreement to ±200 cm^—1 was obtained.