HNO(H2O) n (n=1-4) clusters: a theoretical study

The geometrical structure, binding energy, and vibrational spectra of small clusters of nitrosyl hydride (HNO) and water molecules, HNO(H2O) (n) , where (n = 1-4), have been investigated at the MP2 level of theory, using 6-311++G(2d,2p) basis set. We located three dimers, six trimers, nine tetramers, and three pentamers at the MP2/6-311++G(2d,2p) computational level. Particular attention is given to existence and magnitude of NH center dot center dot center dot O blue-shifting hydrogen bonds. Blue shifts of the NH stretching frequency upon complex formation in the ranges between 28 and 151 cm(-1) is predicted. Cooperative effect in terms of stabilization energy along with the many-body interaction energies analysis was performed for the studied clusters. The Atoms in Molecules (AIM) theory was also applied to explain the nature of the complexes.