Müller P C, Elliott S R, Dronskowski R, Jones R O
Lehrstuhl für Festkörper- and Quantenchemie, Institut für Anorganische Chemie, RWTH Aachen University, D-52056 Aachen, Germany.
Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom.
J Phys Condens Matter. 2024 May 17;36(32). doi: 10.1088/1361-648X/ad46d6.
Almost all phase-change memory materials (PCM) contain chalcogen atoms, and their chemical bonds have been denoted both as 'electron-deficient' [sometimes referred to as 'metavalent'] and 'electron-rich' ['hypervalent', multicentre]. The latter involve lone-pair electrons. We have performed calculations that can discriminate unambiguously between these two classes of bond and have shown that PCM have electron-rich, 3c-4e ('hypervalent') bonds. Plots of charge transferred between () and shared with () neighbouring atoms cannot on their own distinguish between 'metavalent' and 'hypervalent' bonds, both of which involve single-electron bonds. PCM do not exhibit 'metavalent' bonding and are not electron-deficient; the bonding is electron-rich of the 'hypervalent' or multicentre type.
几乎所有的相变存储材料（PCM）都含有硫族原子，其化学键既被称为“缺电子”（有时也称为“亚价”），也被称为“富电子”（“超价”、多中心）。后者涉及孤对电子。我们进行了能够明确区分这两类键的计算，并表明PCM具有富电子的3c - 4e（“超价”）键。在（）与相邻原子（）之间转移和共享的电荷的图本身无法区分“亚价”键和“超价”键，这两种键都涉及单电子键。PCM不表现出“亚价”键合，也不是缺电子的；其键合是“超价”或多中心类型的富电子键合。
