Structures, energetics, and spectra of OH−(H2O)n and SH−(H2O)n clusters, n=1–5: Ab initio study

OH − ( H 2 O ) n and SH−(H2O)n (n=1–5) clusters have been studied using ab initio calculations. The relative stabilities of various isomers of SH−(H2O)n are quite different from those of the corresponding isomers of OH−(H2O)n (n=3–5) at 0 K, and are almost the same as those of the corresponding isomers of OH−(H2O)n at 298 K. That is, the relative stabilities of various isomers of SH−(H2O)n and OH−(H2O)n at 298 K are quite different from those at 0 K due to the entropy effect. The ionization potential, charge-transfer-to-solvent energy, and OH stretching vibrational spectra are reported to facilitate future experimental work.