"Actually I did. I said that it is immaterial whether any such atheistic govt has ever existed (which I do not believe to be the case and perhaps you could enlighten us if there ever was one), Stalin and Mao do not represent such a govt. "

Stalin was "Comrade" Stalin, in an officially atheistic state. He was not Pope Stalin or God Stalin. His rule was enforced by the security services. Not by the promise of heavenly rewards or punishment. There are man flags here and statues of historical figures and pictures of people on the stamps and money. That is nationalism, not religion in any conventional sense. The concept could hardly be simpler.
What is below is from Wiki, I have read it elsewhere and studied it in University. But feel free to keep pulling things from your butt, as I will feel free to ignore the things you pull from your butt.

The Soviet Union was the first state to have as an ideological objective the elimination of religion[1] and its replacement with atheism as a fundamental ideological goal of the state.[2][3] Toward that end, the communist regime confiscated religious property, ridiculed religion, harassed believers, and propagated atheism in the schools.[4] The confiscation of religious assets was often based on accusations of illegal accumulation of wealth.

State atheism in the Soviet Union was known as "gosateizm,[5] and was based on the ideology of Marxism–Leninism. As the founder of the Soviet state V. I. Lenin put it:

    Religion is the opium of the people: this saying of Marx is the cornerstone of the entire ideology of Marxism about religion. All modern religions and churches, all and of every kind of religious organizations are always considered by Marxism as the organs of bourgeois reaction, used for the protection of the exploitation and the stupefaction of the working class.[6]