Computer Simulation of the Total Energy and the Screening Function of a Nitrogen Molecule in First-Order Perturbation Theory.

Within the framework of a new approach to the problem of calculating the total energy of a diatomic molecule in first-order perturbation theory, it is shown that the potential-energy screening function is a solution to a diffusion-type equation in which the role of a time variable is played by the mean square of the amplitude of collective oscillations of electrons per degree of freedom. The total energy of a diatomic nitrogen molecule in the ground and excited states is calculated in first-order perturbation theory using tabulated eigenfunctions and eigenvalues of the energy of isolated atoms, which approximate solutions of the Hartree–Fock equation. The reliability of the numerical method for calculating the total energy of a diatomic nitrogen molecule in first-order perturbation theory is verified using an exact solution with an atomic form factor for the screened Coulomb potential. The new approach to the problem of calculating the total energy of a diatomic molecule in first-order perturbation theory does not contain free parameters, but is based on the numerical solution of a system of nonlinear equations. [ABSTRACT FROM AUTHOR]