Structures and energies of low-lying isomers of Zn x Se x (x =1–4) clusters have been explored with the B3LYP, MP2, and CCSD(T) methods using a basis set of 6-31G(d). Counterpoise (CP)-corrected single point energy calculations on the CP-B3LYP/6-31G(d)-optimized geometries indicate that a singlet D nh (n=2–4) isomers are lowest in energy in the respective Zn x Se x (x=2–4) clusters. We report the CP-corrected electronic, zero-point vibrational, thermal, and interaction energies, and geometrical parameters of the various isomers on the CP-B3LYP-optimized structures. The CP correction leads to significant reduction of the stabilization energy of clusters and lengthening of the intermolecular distance. A D 3h Zn 3 Se 3 complex and D 4h and T d Zn 4 Se 4 isomers having either a planar or tetrahedral geometry are found to be significantly stabilized owing to extensive bonding presumably involving ionic contribution.