Home › Forums › density functional theory › the Born-Oppenheimer approximation › Phonons This topic has 0 replies, 1 voice, and was last updated 2 years, 2 months ago by jnunez. Viewing 1 post (of 1 total) Author Posts October 10, 2022 at 3:41 am #7053 jnunezParticipant The BOA cannot be used to calculate phonons simply because the ions must be considered to be moving 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