“…First, we consider the basis sets effects for the ZnO dimer. In Table 1 we present the computed interatomic distances r e , vibrational frequencies ω e , dissociation energies D 0 , singlet-triplet state splittings The basis extensions lead to a larger ω e value bringing it in better agreement with experiment (811 cm −1 and 805±40 cm −1 ) 47,48 . Both CCSD(T) 41 and most DFT methods seem to somewhat underestimate it; however, there are also other experiments 49,50 which predict the ω e value as 769 cm −1 and 738 cm −1 respectively, it appears that Note: Here, r e is the bond length, ω e is the harmonic vibrational frequency, D 0 is the dissociation energy, T e is the triplet-singlet splitting energy, EA is the electron affinity, q NBO is the atomic charge according to NBO, μ is the computed dipole moment, μ NBO is the dipole moment evaluated using the NPA charges on atoms.…”