To begin the work of the group, Slater "distilled his experience with the Hartree self-consistent field method" into (1) a simplification that became known as the Xα method, and (2) a relationship between a feature of this method and a magnetic property of the system. These required computations that were excessive for "pencil and paper" work. Slater was quick to avail the SSMTG of the electronic computers that were being developed. An early paper on augmented plane waves used an IBM card programmed calculator. The Whirlwind was used heavily, then the IBM 704 in the MIT Computation Center and then the IBM 709 in the Cooperative Computing Laboratory (see below).