A new electron pairing scheme, rectifying a fundamental flaw of the BCS theory, is tested ex- tensively. It postulates that superconductivity arises solely from residual umklapp electron-phonon scattering when it is not in competition for the same destination electron states with normal scat- tering. 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 calcu- late the superconductive electron-phonon spectral density, α2F(ν), entirely on the basis of normal state electrical resistivity. This leads to first principles superconductive properties (zero tempera- ture 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 9.5K for niobium to 0.012K for tungsten.
- superconductors, normal-umklapp frustration, electron pairing, first principles calculation