Further test of new pairing scheme used in overhaul of BCS theory

• Explanation of a new pairing scheme to overhaul BCS theory.
• Prediction of superconductor properties from normal state resistivity.
• Applications to Nb, Pb, Al, Ta, Mo, Ir and W, TcTc between 9.5 and 0.012 K.
• High accuracy compared with measured energy gap of Nb, Pb, Al and Ta.
• Prediction of energy gap for Mo, Ir and W (so far not measured).

A new electron pairing scheme, rectifying a fundamental flaw of the BCS theory, is tested extensively. It postulates that superconductivity arises solely from residual umklapp scattering when it is not in competition for the same destination electron states with normal scattering. It reconciles a long standing theoretical discrepancy in the strength of the electron–phonon interaction between the normal and superconductive states. The new scheme is exploited to calculate the superconductive electron–phonon spectral density, α2F(ν)α2F(ν), entirely on the basis of normal state electrical resistivity. This leads to first principles superconductive properties (zero temperature energy gap and tunnelling conductance) in seven metals which turn out to be highly accurate when compared with known data; in other cases experimental verification is invited. The transition temperatures involved vary over almost three orders of magnitude: from 9.5 K for niobium to 0.012 K for tungsten.