Energetic Factors in Heterogeneous Catalysis

The structural aspect of multiplet theory has been considered in Section I the energy aspect of the theory will be dealt with here. 

According to the multiplet theory the principle of structural correspondence alone is insufficient to explain the course of catalytic reactions and the selectivity of the catalytic effect. 

for example, thoria, Th02, and calcium fluoride, CaF2, are known to possess the same structure (Fig. 39) and practically the same 

Lattice CaFa or ThOa) of the type Cl [sections, parallel to (100)]. Atoms Ca (or Th) form a face-centered lattice of the type Al, the middle of the octantes of cell of which is occupied by the atoms F (or O). Similar to each other are the radii of the atoms Ca 0.99 and O — 1.0 A, as well as Th = 1.40 and F = 1.36 A. This figure shows the arrangement of the atoms but not their dimensions. 

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