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Origin of incommensurate modulations in the high-pressure phosphorus IV phase

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Original languageEnglish
Article number054120
Pages (from-to)-
Number of pages9
JournalPhysical Review B: Condensed Matter and Materials Physics
Volume78
Issue number5
DOIs
Publication statusPublished - Aug 2008

Abstract

We present results from x-ray diffraction experiments and density functional theory calculations which provide a fully consistent picture of the high-pressure phosphorus-IV phase (P-IV). P-IV has an incommensurately-modulated crystal structure described by the four-dimensional superspace group Cmmm(00 gamma)s00. Electronic structure calculations using a three-dimensional commensurate approximant to this structure give excellent agreement with experiment for the structural parameters and their variation with pressure. Density functional perturbation theory shows a phonon instability at the incommensurate wave vector, related to the opening of a pseudogap at the Fermi surface, showing that the atomic motions comprising the incommensuration occur to eliminate Fermi-surface nesting. Unusually, the pseudogap opens not at the incommensurate wave vector (00 gamma) itself, but at two larger wave vectors corresponding to strong reflections in the diffraction pattern.

    Research areas

  • ELECTRON LOCALIZATION, ENERGY, PSEUDOPOTENTIALS, TRANSITIONS

ID: 1277707