Giant electron-phonon interactions in molecular crystals and the importance of nonquadratic coupling

Article

关键词: QUANTUM MONTE-CARLO;    TEMPERATURE-DEPENDENCE;    BAND-GAP;    EXCHANGE;    ABSORPTION;    DIAMOND;    ISOTOPE;    SOLIDS;   

DOI  :  10.1103/PhysRevB.92.140302

来源: SCIE

【 摘 要 】

We investigate electron-phonon coupling in the molecular crystals CH4, NH3, H2O, and HF, using first-principles quantum mechanical calculations. We find vibrational corrections to the electronic band gaps at zero temperature of -1.97 eV, -1.01 eV, -1.52 eV, and -1.62 eV, respectively, which are comparable in magnitude to those from electron-electron correlation effects. Microscopically, the strong electron-phonon coupling arises in roughly equal measure from the almost dispersionless high-frequency molecular modes and from the lower-frequency lattice modes. We also highlight the limitations of the widely used Allen-Heine-Cardona theory, which gives significant discrepancies compared to our more accurate treatment.

【 授权许可】

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