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, 6 days ago by rashurko. Viewing 1 post (of 1 total) Author Posts September 29, 2025 at 1:31 pm #13248 rashurkoParticipant The Born-Oppenheimer approximation is not valid when we try to calculate the rotational and vibrational states of a solid (when nuclei move quite a bit). 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