Structure of A15 compounds

According to the physical properties, chemical structures, and atomic coordination details of constituents of A15 compounds, a set of atomic radii of binary A15 compounds is given as the result of a calculation, which consist of the radical constituent radii r/sub A/ and non-radical constituent radii r/sub B/; and gives a new calculation pattern of lattice constant of A15 compounds: a = 4/√ 5(r/sub A/ + r/sub B/). The errors of calculated values from experimental results are less than 0.0009 nm, whereas those at the present international level are less than 0.003 nm. It is suggested that the empty nd band of elements in the echelon region has in its turn a hand in bonding during the formation of A15 compounds, and hence it has influence on the A-A chain. (author)