ABSTRACT
A Nobel prize was awarded for the invention of an approximation method that can calculate the quantum mechanical ground state of many-electron systems. This breakthrough was based, not on the invention of a new numerical method or algorithm, nor on the implementation of one, but on an approximate reformulation of the governing equation. This last chapter illustrates the power of reformulating equations to make them amiable to numerical solution. It also places us in the realm of partial different equations that are boundary value problems. The chapter, and the main text of the book, ends with an outline of the Density Functional Method, for which the prize was given.
