Knowledge Bank

A large number of phenomena such as `energy of activation' of a reaction and the mechanism of catalyst could be interpreted if it were possible to divide the energy of activation ($ϵnet$) in two parts, that is $ϵact=ϵ1+ϵ2$. This energy of activation of a substrate could donate $ϵ2$ part of the energy to the antibonding orbital of the enzyme having energy level of the the order of $ϵ2$, thus lower activation energy. Therefore, an attempt has been made to form the doubly excited states of CO and $N2$ and calculate the energy of the doubly excited orbitals by subtracting the energy of the excited state from that of the ground state of the molecule. Similar calculations have been carried out for the known singly excited states of these molecules. In both cases an independent check of the energies has been made by the application of the well known Koopmans' theorem. The configuration along with total energy of the doubly excited states and the results of the computation of the excitation energies will be discussed.