We study the effect of quantum vibronic coupling on the electronic properties of carbon allotropes, including molecules and solids, by combining path integral first principles molecular dynamics (FPMD) with a colored noise thermostat. In addition to avoiding several approximations commonly adopted in calculations of electron-phonon coupling, our approach only adds a moderate computational cost to FPMD simulations and hence it is applicable to large supercells, such as those required to describe amorphous solids. We predict the effect of electron-phonon coupling on the fundamental gap of amorphous carbon, and we show that in diamond the zero-phonon renormalization of the band gap is larger than previously reported.
Quantum vibronic effects on the electronic properties of solid and molecular carbon / Kundu, Arpan; Govoni, Marco; Yang, Han; Ceriotti, Michele; Gygi, Francois; Galli, Giulia. - In: PHYSICAL REVIEW MATERIALS. - ISSN 2475-9953. - 5:7(2021), pp. L070801-L070801. [10.1103/physrevmaterials.5.l070801]