The mixed (H 2 O) m (H 2 S) n clusters have not been studied as much as water and hydrogen sulphide clusters. In the literature, two conformers of (H 2 O) 1 (H 2 S) 1 dimer, one having O-H…S and the other having S-H…O HB were proposed and observed in cryogenic matrix. Tremblay et al. shows the conformers of (H 2 O) 1 (H 2 S) 2 and (H 2 O) 2 (H 2 S) 1 of mixed trimers in the Ne gas matrix. Novoa et al. reported the BE (18.73 kcal mol -1 ) for (H 2 O) 1 (H 2 S) 1 dimer. They also studied the neutral (H 2 O) m (H 2 S) where m = 4 cluster and reported the zero-point corrected interaction energy (16.97 kcal mol -1 ) at MP2/ TZ94+P level. Hillier et al. reported three minimum energy structures for m = 4 cluster with relative energy (16.50 kcal mol -1 ) at MP2/6-311++g** level. They also reported four structures for m = 7 clusters with relative energy (RE) 10.20 kcal mol -1 at the same level of theory.