Ionicity,atomic radii,and structure in the layered dichalcogenides of group IVb,Vb, and VIb transition metals

Pauling's electronegativities are introduced in considerations of bond lengths, lattice constants, atomic radii, charge densities, structures, and heats of formation of the layered dichalcogenides of Groups IVb, Vb, and VIb transition metals. Strong correlations are found between these and the fractional ionic character of the metal-chalcogen bonds as defined by Pauling. A critical effective radius ratio is defined that separates trigonal prismatic and octahedral compounds.