Abstract

GONZALEZ, Leonardo. GOLDSCHMIDT ATOMIC DIAMETER AND PAULING EQUATION. uct [online]. 2010, vol.14, n.54, pp.005-018. ISSN 1316-4821.

Atomic size is an important factor in processes such as diffusion and also in crystallographic structure configuration. But a question arises. What is the size of an atom? As an atom in practically empty, then its size must be related to their outer electrons and their neighbor atoms. First is called its valency numbers, valency electrons or bond electrons and the second one its coordination number. When the coordination number is twelve (12) and the crystal system is hcp, the atomic diameter so determined is called Goldschmidt atomic diameter. Linus Pauling developed a simple equation to calculate Goldschmidt atomic diameter in bcc and fcc structure. As valency is an important factor in Pauling’s equation he gives to this factor a relevant importance. In this paper, Pauling’s equation and his method of calculus is carefully analyzed concluding that Goldschmidt atomic diameter calculated by using this equation is independent of valency number. Inspired in the Pauling´s equation a new model for length bond calculation is proposed, which has been applied successfully to vitreous selenium and a new model for eutectoid reaction in hypoeutectoid steels.

Keywords : Coordination Number; Electron-Bond; Atomic bond; Goldschmidt Atomic Diameter; Pauling’s Equation.