Spectrum of UCl4

Abstract

The spectrum of thin single crystals of UCl₄ was obtained at liquid‐helium temperature. Under these conditions it was possible to resolve what usually appear as broad bands into groups of lines. By utilizing polarization spectra, line position, and line appearance, it was possible to assign transitions between crystal field states. Knowing the position of the crystal field states allowed calculation of the position of the field‐free ion J levels and ^2s+1L terms. Configuration interaction is discussed on the basis of the variation of these terms. Results of this study which might pertain to magnetic susceptibility measurements, covalent bonding considerations, f‐orbital formation, and descriptions of 5f eigenfunctions are mentioned.