LOCAL-STRUCTURE AND LOCAL SYMMETRY IN DILUTE-SOLUTIONS

This paper presents a novel application of symmetry, namely to the ana lysis of the structure induced in a solvent by the presence of the sol ute molecules. The method combines symmetry projection operator techni ques with the concept of local high-symmetry sites within the solute m olecule so as to generate families of symmetry adapted radial distribu tion functions (SARDFs) that are designed to highlight the structuring effect of the solute on the solvent. The technique is simple to imple ment, and provides significant new information that is not available f rom the more conventional methods of analysis. As illustrative example s, the SARDFs are used to examine the solvation structure around cycli c ketones in organic solvents, and around tert-butanol in water. In th e latter case, the method produces clear evidence that structuring of the solvent is maximised when hydrogen-bonding interactions between th e solute and solvent are of intermediate strength.