From X alpha-scattered wave to end-of-the-century applications of density functional theory in chemistry. Perspective on "Chemical bonding of a molecular transition-metal ion in a crystalline environment" - Johnson KH, Smith FC Jr (1972) Phys Rev B 5 : 831-843

The pager by Johnson and Smith is representative of the X alpha-scattered w ave (SW) effort of the 1970s. Despite the severe approximations that were n ecessary at the time, the paper shows that a "first-principles" X alpha cal culation yields a compelling account of the electronic structure and spectr um of permanganate. Contemporaneous semiempirical and ab initio calculation s were not up to the task. The quality of the results and the prospect of t reating really large systems were sufficient to attract the attention of ma ny quantum chemists (as well as the disdain of some and the ire of others). The X alpha-SW work was an important link in the chain of contributions th at would bring density functional theory into chemistry.