Home › Forums › density functional theory › the Born-Oppenheimer approximation › where the Born-Oppenheimer approximation may not be valid This topic has 0 replies, 1 voice, and was last updated 1 year, 4 months ago by sadiasalsabil. Viewing 1 post (of 1 total) Author Posts August 16, 2023 at 1:38 am #8768 sadiasalsabilParticipant Probably in gases, because the motion is random. 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