Heteronuclear intervalence transitions

2 Heteronuclear intervalence transitions involve different cations. An example involving the octahedral Fe2+ and Ti4 cation pair, may be depicted by 

Examples of silicate and oxide minerals showing IVCT transitions are summarized in table 4.2. Most IVCT transitions take place between octahedrally coordinated cations, although examples involving octahedral-tetrahedral (e.g., cordierite) and cubic-tetrahedral (e.g., garnet) pairs are known. An IVCT transition most commonly occurs between cations located in edge-shared coordination polyhedra, although several examples involving face-shared octa- 

Mineral M-M IVCT Molar Half- Sources of data Symbol in 

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