A potential model represented by the overlap of electron clouds of interacting particles has been applied to discuss the diabatic potential crossings, which lead to excitations of N-2(a(1)Pi (g)) and CO(A(1)Pi) in moderate-energy Li+-N-2 and Li+-CO collisions, at the specific molecular orientations of gamma = 0 degrees and 180 degrees (linear configuration). The potential crossings in the overlap model originate from the hole produced by the promotion of an electron in the outer a molecular orbitals (MOs) of the N-2 and CO molecules.