We have extracted consistent phonon dispersion information out of rather inconsistent vanadium x-ray scattering data from synchrotron and vacuum tube sources. With this and a new theoretical approach we have made firm predictions for the tunnelling conductance of superconducting vana- dium; it is in unusually poor agreement with experimentally measured values. We argue that the problem lies in the experimental measurement rather than the theory. The preparation of a suitable high quality tunnel barrier on vanadium represents an outstanding challenge.
- vanadium, phonons, electron pairing, coulomb pseudopotential, superconductivity prediction