Abstract
The Fermi surface, phonon spectrum, and electron-phonon coupling parameter for metallic Nb under high pressure have been investigated with a full potential linearized augmented plane wave, linear muffin-tin orbital, and pseudopotential plane-wave methods. The results support the experimental observation of electronic topological transitions at 5 and 60 GPa. The lower pressure transition is related to a very subtle change in the topology of the Fermi surface as revealed in accurate calculations of the Hall coefficient. The transition at 60 GPa is identified with a change in the Fermi-surface topology due to the crossing of the electronic band along the (Σ) direction in the cubic Brillouin zone. The calculated electron-phonon coupling parameters are in qualitative agreement with those derived from high-pressure experiment.
- Received 27 November 2003
DOI:https://doi.org/10.1103/PhysRevB.69.132101
©2004 American Physical Society