A simplistic computational procedure for tunneling splittings caused by proton transfer

Abstract In this manuscript, we present an approach for computing tunneling splittings large amplitude motions. The core of the is a solution effective one-dimensional Schrödinger equation with mass and potential energy surface composed electronic harmonic zero-point vibrational energies small motions in molecule. method has been shown to work cases three model motions: nitrogen inversion ammonia, single proton transfer malonaldehyde, double formic acid dimer. current work, also investigate performance different DFT post-Hartree–Fock methods prediction splittings, quality parameters upon isotopic substitution, possibility complete basis set (CBS) extrapolation resulting splittings.