No. And
here is why...
The most important points from the link (though I do suggest you click on the link to read the rest)...
1. Atheism is not an "Ism"
When people talk about "isms," they are referring to some "distinctive doctrine, theory, system, or practice" like liberalism, communism, conservatism, or pacifism. The suffix "ism" also means a "state, condition, attribute, or quality" like pauperism, astigmatism, heroism, anachronism, or metabolism. Is astigmatism a theory? Is metabolism a doctrine? Is anachronism a practice? Not every word that ends in "ism" is a system of beliefs or an "ism" in the way people usually mean it.
2. Atheism Is Not An Ideology
An ideology is any "body of doctrine, myth, belief, etc., that guides an individual, social movement, institution, class, or large group." There are two key elements necessary for an ideology: it must be a group of ideas or beliefs and this group must provide guidance. Neither is true of atheism. First, atheism is by itself just the absence of belief in gods; it's not even a single belief, much less a body of beliefs. Second, atheism by itself offers no guidance on moral, social, or political matters. Atheism, like theism, can be part of an ideology, but neither can be an ideology by themselves.
3. Atheism Is Not A Philosophy
A person's philosophy is their "system of principles for guidance in practical affairs." Like ideology, a philosophy comprises of two key elements: it must be a group of beliefs and it must provide guidance. Atheism is not a philosophy for the same reason that it is not an ideology: it's not even a single belief, much less a system of interconnected beliefs, and by itself atheism does not guide anyone anywhere.
4. Atheism Is Not A Belief System
A belief system is a "faith based on a series of beliefs but not formalized into a religion; also, a fixed coherent set of beliefs prevalent in a community or society." This is simpler than an ideology or philosophy because it's just a group of beliefs; they don't have to be interconnected and they don't have to provide guidance. This still doesn't describe atheism; even if we narrowed atheism to denying the existence of gods, that's still just one belief and a single belief is not a set of beliefs. Theism is also a single belief that is not a belief system. Both theism and atheism are part of belief systems, though.
To me, even the term "atheism" is one I detest, despise and abhor beyond measure. To me, God(s) is/are nothing more than (a) mythological figure(s). There is no word for someone who does not believe in Zeus, Dionysus, The Flying Spaghetti Monster or The Tooth Fairy, nor should there be one for someone who does not believe in God(s).