Resonating-valence-bond contribution to superconductivity in MgB2 -: art. no. 212505

We view MgB2 as electronically equivalent to (nonstaggered) graphite (B- layer) that has undergone a zero-gap-semiconductor-to-superconductor phase transition by large c-axis (chemical) pressure due to Mg++ layers. Further, like the ppi-bonded planar organic molecules, graphite is a resonating-valence-bond (RVB) system. The RVB's are the preexisting Cooper pairs in the parental zero-gap semiconducting B- (graphite) sheets that manifest themselves as a superconducting ground state of the transformed metal. Some consequences are pointed out.