Meta-screening and permanence of polar distortion in metallized ferroelectrics

Work supported by the Luxembourg National ResearchFund through Grant No. P12/4853155 COFERMAT (H.J.Z.and J.I.), INTER/MOBILITY/15/9890527 GREENOX (L.B.,H.J.Z., and J.I.), and AFR Grant No. 9934186 (C.E.S.).Additionally, V.F. was supported by Progetto biennale diateneo UniCA/FdS/RAS 2016; E.C. by the Spanish MINECOthrough the Severo Ochoa Centers of Excellence Programunder Grant No. SEV-2015-0496, as well as through GrantNo. FIS2015-64886-C5-4-P, and by Generalitat de Catalunya(Grant No. 2017SGR1506); and L.B. by the Air Force Officeof Scientific Research under Grant No. FA9550-16-1-0065.Computational resources have been provided by the PRACE-3IPDECI-13Grant No. 13DECI0270INTERPHON(Salomoncluster at the Czech National Supercomputing Center), theCRS4 Computing Center (Piscina Manna, Pula, Italy), and theArkansas High Performance Computing Center. Also, we aregrateful to M. Stengel and P. Zubko for fruitful discussions.