Computational analysis of uranyl silicates using Gaussian 98

The structures of three uranyl silicate complexes were optimized and analyzed using the Gaussian.98 computational program. Each complex contains a uranyl portion (UO[subscript]2) that is attached to a silicate base (Si0[subscript]2) to form a "bridged" complex. The monosilicate complex contained one silicate base, while the disilicate had two. There were two different bridged disilicate complexes to represent the symmetrical complex where the uranyl molecule is placed between two silicate bases and the unsymmetrical complex with the uranyl attached to a silicate base dimer. The purpose of this study is to investigate the complex formation between the uranyl ion and a silicate base structure, analyze the thermodynamic properties of each structure and the bonding nature of the various bonds within the complexes and compare them to experimental work, as well as to validate the concept of the "colloidal transport system".