Valence distance, constancy

By rc ason of this general constancy of th( primary valence bonds, quite sharp limitations are placed upon the basic assumptions of stereochemistry which are fully confirmed by modern research. These limitations restrict the possibility of synthesizing organic molecules and exclude many of those formulae previously used for purposes of convenience in designing structural formulae on paper. Our present knowledge authorizes and compels us to recognize and apply the constancy of the valence distances as an experimentally well-founded law in proposing any structural formula. It will be shown later by a few example s how important the consistent employment of this important principle has become in individual cases. 

But apart from this effect of higher order, the extent of which amounts to a few percent, we may consider the law of the constancy of valence distances as applicable to the topics following and, in particular, to the discussion of highly polymerized substances. 

Depending on various location. Lithium atoms have different coordi-native valences those placed in (8) tetrahedral interstices have CN=4, and those placed in (4) octahedral interstices have CN=6. Yet, the constancy coordination law imposes that the Bismuth atoms to have CN = (8.4 + 4.6)/4 = 14. Indeed, each atom of Bi is surrounded by eight tetrahedral Lithium atoms at a distance ayfi and by 6 octahedral Lithium atoms at a distance all (0.5 a). Coordination polyhedron of the Bismuth atom is the p5rramidal cube. 

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