In 1947, Linus Pauling presented an “empirical” dependence of bond valence (s, also referred to as bond order) and bond length R: s = exp[(R0-R)/b], where R0 is bond length of unit valence and “b” is a fitting parameter. Recently, an expression was derived for relating the b fitting parameter to theoretically derived atomic orbital exponents. With a method to calculate b, both R0 and atomic orbital exponents can be experimentally determined through optimized fitting for W-O and W-S bonds. In the present study, bond length – valence relationships are found for W-O and W-S chemical bonds using published crystallographic data. The atomic orbital exponent for tungsten was found to be zW = 1.534. Unit valence (single bond) bond lengths were found to be Ro(W-O) = 1.901 Å and Ro(W-S) = 2.307 Å.
Hardcastle, F. D. and Lykins, R.
"Bond Length and Bond Valence for Tungsten-Oxygen and Tungsten-Sulfur Bonds,"
Journal of the Arkansas Academy of Science: Vol. 71
, Article 15.
Available at: http://scholarworks.uark.edu/jaas/vol71/iss1/15