Anharmonic electron-phonon coupling in polymorphous perovskites Marios Zacharias (  marios.zacharias@insa-rennes.fr ) Univ Rennes, INSA Rennes, CNRS https://orcid.org/0000-0002-7052-5684 George Volonakis (  yorgos.volonakis@univ-rennes.fr ) Université de Rennes https://orcid.org/0000-0003-3047-2298 Feliciano Giustino (  fgiustino@oden.utexas.edu ) The University of Texas at Austin https://orcid.org/0000-0001-9293-1176 Jacky Even (  jacky.even@insa-rennes.fr ) Institut FOTON UMR CNRS 6082 https://orcid.org/0000-0002-4607-3390 Physical Sciences - Article Keywords: DOI: https://doi.org/ License:   This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License Additional Declarations: There is NO Competing Interest.