TY - JOUR AU - Jones, Robert O. AU - Elliott, Stephen R. AU - Dronskowski, Richard TI - The Myth of “Metavalency” in Phase‐Change Materials JO - Advanced materials VL - 35 IS - 30 SN - 0935-9648 CY - Weinheim PB - Wiley-VCH M1 - FZJ-2023-02346 SP - 2300836 PY - 2023 AB - Phase-change memory materials (PCMs) have unusual properties and important applications, and recent efforts to find improved materials have focused on their bonding mechanisms. “Metavalent bonding” or “metavalency,” intermediate between “metallic” and “covalent” bonding and comprising single-electron bonds, has been proposed as a fundamentally new mechanism that is relevant both here and for halide perovskite materials. However, it is shown that PCMs, which violate the octet rule, have two types of covalent bond: two-center, two-electron (2c-2e) bonds, and electron-rich, multicenter bonds (3c-4e bonds, hyperbonds) involving lone-pair electrons. The latter have bond orders less than one and are examples of the century-old concept of “partial” bonds. LB - PUB:(DE-HGF)16 C6 - 37162226 UR - <Go to ISI:>//WOS:000984957200001 DO - DOI:10.1002/adma.202300836 UR - https://juser.fz-juelich.de/record/1008446 ER -