Home › Forums › density functional theory › the Born-Oppenheimer approximation › Breaking Born Oppenheimer This topic has 0 replies, 1 voice, and was last updated 1 year, 9 months ago by carlosjimenez11. Viewing 1 post (of 1 total) Author Posts March 6, 2023 at 10:10 pm #8433 carlosjimenez11Participant As the approx. is made from the idea of an extremely high mass and velocity difference between the nucleus and the electrons, if the nucleus moves faster (that means, if the system has high energy) the approximation is broken. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In