Home › Forums › density functional theory › the Born-Oppenheimer approximation › Born-Oppenheimer approximation This topic has 0 replies, 1 voice, and was last updated 1 week, 1 day ago by ellen. Viewing 1 post (of 1 total) Author Posts October 4, 2025 at 2:12 pm #13399 ellenParticipant The Born-Oppenheimer approximation might not be valid when the nuclei move fast enough to affect electrons, for example at very high temperatures or for very light nuclei. 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