1) Deity disbelievers 2) Disbelieving ones 3) Naysayers, of a kind 4) Non-prophet group 5) Nonbelievers 6) Nonbelievers in God 7) Ones in disbelief 8) They believe no deities exist 9) Unbelievers 
Atheist are people who deny the existence of a deity or any fashion of things coplanor toward reality. ...