Yes, a sociopath can be an atheist, just as a sociopath can belong to any religious or non-religious belief system. Sociopathy, or Antisocial Personality Disorder (ASPD), is a mental health condition characterized by a pattern of disregard for and violation of the rights of others. It is a personality disorder that affects an individual's behavior, emotions, and social interactions.
An individual's religious or non-religious beliefs are separate from their mental health condition. Sociopathy does not determine a person's religious or spiritual beliefs. People with ASPD may have a wide range of beliefs or non-beliefs, just like any other individual.
It is important not to conflate mental health conditions with personal beliefs. Mental health conditions are medical conditions that require understanding, empathy, and appropriate treatment, while personal beliefs are a matter of individual choice and can vary greatly from person to person.