Is MgB2 a BCS-like charged superfluid?

Two complementary mechanisms have been proposed for relatively high temperature superconductor MgB2. While the first is the electron-phonon mechanism of BCS theory, advocated strongly by Pickett and co-workers, the second, by Bianconi el al., invokes Feshbach shape resonances. While we cannot presently discount the second mechanism, and while both proposals exploit the multiband nature of the electronic structure of MgB2, we show here that five body-centred cubic (bee) transition metals, whose superconducting transition temperature correlate intimately with elastic constants and therefore are plainly BCS-like in character, lie on a curve which has MgB2 at the high T-c end. Any alternative mechanism to electron-phonon interaction in MgB2 will need to account quantitatively for this circumstance.