Configurational Sampling of Noncovalent (Atmospheric) Molecular Clusters: Sulfuric Acid and Guanidine

We
studied the configurational sampling of noncovalently bonded
molecular clusters relevant to the atmosphere. In this article, we
discuss possible approaches to searching for optimal configurations
and present one alternative based on systematic configurational sampling,
which seems able to overcome the typical problems associated with
searching for global minima on multidimensional potential energy surfaces.
Since atmospheric molecular clusters are usually held together by
intermolecular bonds, we also present a cost-effective strategy for
treating hydrogen bonding and proton transferring by using rigid molecules
and ions in different protonation states and illustrate its performance
on clusters containing guanidine and sulfuric acid.