Allosteric (conformation changing) proteins with transition metal atoms are at the heart of much important biological function (e.g., myoglobin hemoglobin used for storing and transporting oxygen in the bloodstream). In the case of myoglobin and hemoglobin, oxygen ligation to the iron center induces a spin crossover (high to low) coupled to a structural change; apart from the role of Hunds' exchange in the spin crossover, electron interaction effects have been ignored. We argue that the spin crossover/structure change observed in the similarly structured but far simpler cobalt valence tautomer molecules1 necessitates an inclusion of underscreened Kondo like correlations for a complete description of the energetics of the transition and dynamics, e.g., for x-ray absorption data. We carry this study out with Varma-Yafet-Gunnarsson-Schonhammer wave functions, which, in chemistry language, are basis set restricted configuration interaction in character. We briefly review the applicability of such wave functions to the description of the putative Kondo molecules cerocene (Ce[(CH)5]2) and ytterbocene bipyridine (Yb[(CH)5]2(bipy)) and to the problem of electron transfer in biological molecules and organic conductors, where anomalous long range tunneling may occur. Research supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Division of Materials Research.