Abstract
Density functional theory is generalized to incorporate electron-phonon coupling. A Kohn-Sham equation yielding the electronic density nU(r), a conditional probability density depending parametrically on the phonon normal mode amplitudes U={Uqλ}, is coupled to the nuclear Schrödinger equation of the exact factorization method. The phonon modes are defined from the harmonic expansion of the nuclear Schrödinger equation. A nonzero Berry curvature on nuclear configuration space affects the phonon modes, showing that the potential energy surface alone is generally not sufficient to define the phonons. An orbital-dependent functional approximation for the nonadiabatic exchange-correlation energy reproduces the leading-order nonadiabatic electron-phonon-induced band structure renormalization in the Fröhlich model.
Original language | English |
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Article number | 165136 |
Journal | Physical Review B |
Volume | 99 |
Issue number | 16 |
DOIs | |
State | Published - 24 Apr 2019 |
Bibliographical note
Publisher Copyright:© 2019 American Physical Society.