On my return to Pittsburgh, I resolved to go back to the fundamental problems of electronic structure that I had contemplated abstractly many years earlier.

While in the early days these calculations were extremely expensive to perform the advent of high speed microprocessors has made them much more feasible today. Subsequently he developed the methods of Complete Neglect of Differential Overlap (CNDO) (in 1965) and Intermediate Neglect of Differential Overlap (INDO) for approximate MO calculations on three-dimensional molecules and other developments in computational chemistry. He moved to the United States of America in 1964 where he lived the rest of his life though he retained British citizenship.

A. Sir John Anthony Pople KBE FRS (October 31 1925 – March 15 2004) was a Nobel-Prize winning theoretical chemist. He moved to the United States of America in 1964 where he lived the rest of his life though he retained British citizenship.