Non‐born–oppenheimer density functional theory for excited states by using green's function techniques

We have proposed a numerical scheme for the non‐Born–Oppenheimer density functional calculation based upon the Green function techniques within the GW approximation for evaluating quasiparticle excitations of the electronic and nuclear motion in the full quantum mechanical treatment. We calculate the excitation energy and the orbital energy of a hydrogen molecule, a muon molecule, and a positronium–hydrogen complex within the treatment of the dynamical screening. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem 84: 354–362, 2001