In a famous quote from his 1929 account on many-electron systems 4 , Dirac emphasized the importance of his discovery and then continued to state that it "becomes desirable that approximate practical methods of applying quantum mechanics should be developed, which can lead to an explanation of the main features of complex atomic systems without too much computation." This desire has been the motivation for generations of computational chemists and physicists to devise algorithms that allow us to solve the differential equations governing the dynamics of many-electron systems.