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, 2 days ago by Tomas Verbist. Viewing 1 post (of 1 total) Author Posts October 3, 2025 at 7:25 pm #13387 Tomas VerbistParticipant I would think that this approximation would break down when the masses of the nuclei are small en their speed cannot be considered negligible compared to the electron speed (at high temperature for example). 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