Theoretical study and atoms in molecule analysis of hydrogen bonded clusters of ammonia and isocyanic acid

Abstract  

Ab initio and density functional calculations were used to analyze the interaction between a molecule of the isocyanic acid with 1 up to 4 molecules of ammonia at the B3LYP/6-311++G(d,p) and MP2/6-311++G(d,p) computational levels. The cooperative effect is increased with the increasing size of studied clusters. Red shifts of the H–N stretching frequency for complexes involving the isocyanic acid as an H-donor were predicted. Atom in molecules was used to analyze cooperative effects on topological parameters.