When in the hell did someone start going around and making their own definition of atheism?
a·the·ist
n.
One who disbelieves or denies the existence of God or gods.
WTF does the above definition have to do with chemical reactions of the belief in good and evil? Stop being an evil asshat and move on! Quit trying to make every damn thing religious. If you can't deal with your own belief system without trying to convince everyone else, then you don't believe in it yourself. It's like walking around with swishing hips, tight jeans and a rainbow colored t-shirt tied in a knot in the middle of your flat, hairless chest and proclaming loudly in a feminine tone with a lisp that you're not gay. You're only fooling yourself at the end of the day.