The Gibbs-free-energy difference ΔGt which determines the phase transition from fourfold to sixfold coordination in ANB8-N compounds is presented for three compounds (CdO, MgO, and AgBr) which are stable at STP in the more-dense (NaCl) structure. The additional data follow a linear trend in spectroscopic ionicity predicted previously from high-pressure data on compounds stable in fourfold coordinated structures. These data resolve ambiguities concerning the proper definition of ionic character in partially covalent compounds with the NaCl structure.
ASJC Scopus subject areas
- Condensed Matter Physics