Structural parameters and unit cell dimensions for the tetragonal actinide tetrachlorides(Th, Pa, U, and Np) and tetrabromides (Th and Pa)

Abstract

Comparison of crystal structure parameters obtained for ThCl₄ from quantitative X-ray powder data with those available from single-crystal studies has shown that it is possible to obtain reliable parameters from powder studies on simple compounds. Structure refinement based on powder data for ThCl₄(R= 8·9%), PaCl₄(R= 7·6%), UCl₄(R= 9·5%), NpCl₄(R= 9·1%), and ThBr₄, (R= 11·3%) has yielded crystal structure parameters, and bond lengths for these isostructural compounds. Accurate unit cell dimensions are also reported.