Potential energy curves and spectroscopic constants for 30 electronic states of Mo 2 + together with the ground states of Mo 2 − anion and Mo 2 have been computed using the complete active space multiconfiguration self-consistent field (CASMCSCF) followed by the multireference singles+doubles configuration interaction (MRSDCI) calculations that included up to 44.4 million configurations. We have reported computed equilibrium distances (r e ), vibrational frequencies (ω e ) and energy separations (T e ). We have predicted several spectroscopic systems for Mo 2 + , which are yet to be observed and the electron affinity of Mo 2 .