valence

molecules with unpaired valence electrons.

The valences of copper are 1 and 2.

The relationship between bond valence and bond covalency has been investigated by a semiempirical method.

A method to calculate new valence electronegativity and the ionicity of chemical bond of the transition metal elements is also presented here.

The photoabsorption spectra in the valence-shell continuum region of C2H4 are calculated by the multi-scattering self-consistent-field method in the framework of the quantum defect theory.