Molecular dynamic study of stabilization of the Cl−−Cl− anion pair in steam

This paper studies the formation of a stable anion pair as a result of cluster interactions with water molecules (the number of molecules n=4, 6, 8, and 14). The hydration shells of the clusters obtained in a preliminary calculation are destructed to form closed chains of properly oriented water molecules in the space between the anions. The type of the resulting structure depends on the number of shared water molecules. The character of stabilization of the anion pair, determined by calculating different energy terms, also changes as n increases. The cyclic structures obtained in the region of the anion pair differ considerably from the structure of isolated Cl⁻ (H₂O)_n clusters and that of the aqueous solution of NaCl. The capture of water molecules by the anion pair is manifested in the nucleation of industrial steam. Institute of Thermal Physics, Ural Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 2, pp. 289–298, March–April, 1996. Translated by L. Smolina