As you like....There is only a correlation in the first statement, not a causation. Atheism, for instance, cannot by definition imply mass murder, since it is the absence of a particular belief. On the contrary, Christianity is an ideology and can thus inspire mass murder. It is like arguing that Stalin was not bald, therefore having hair causes genocide and, indeed, all genocidal dictators have had hair somewhere on their body.
Furthermore, Russia was hardly a socialist country. It was a totalitarian country that practiced the dictatorship of the proletariat. They where trying to reach the no-state, no-class, no-private property ideal of communism by using applied fascism.