Sir John Pople

Nobel Prize winner who applied maths to chemical problems

John Anthony Pople, chemist: born Burnham-on-Sea, Somerset 31 October 1925; Fellow, Trinity College, Cambridge 1951-58; Lecturer in Mathematics, Cambridge University 1954-58; Superintendent, Basic Physics Division, National Physical Laboratory 1958-64; FRS 1961; Professor of Chemical Physics, later John Christian Warner University Professor of Natural Sciences, Carnegie Mellon University, Pittsburgh 1964-93; Adjunct Professor of Chemistry, Northwestern University 1986-93, Trustees' Professor of Chemistry 1993-2004; Nobel Prize for Chemistry 1998; KBE 2003; married 1952 Joy Bowers (deceased; three sons, one daughter); died Chicago, Illinois 15 March 2004.

John Pople's research and development work fundamentally changed the way that the world does chemical science. Pople, Trustees' Professor of Chemistry at Northwestern University, in Evanston, Illinois, since 1993, worked in the area of theoretical chemistry. While he made an enormous number of contributions in this area, probably the most lasting and significant was his development and dissemination of quantum mechanical methods to determine the structure of molecules.

Determining what shape molecules have, and therefore what properties they will exhibit, has been an occupation of chemists for well over a century. With the advent of quantum mechanics in the 1920s, the appropriate mathematical and physical formulation of the problem became clear. Creative work by D.R. Hartree in England and V.A. Fock in Russia permitted accurate understanding of the structure of atoms, but molecules are more complicated because they consist of many atoms, and the relative arrangement of these atoms is a question of major importance.

Such structures can be determined using physical methods, but these are often difficult to apply. Since almost all of chemistry is determined by the structure and properties of molecules, this understanding is critical for progress in the chemical sciences. Moreover, since molecules are found throughout the biosphere and atmosphere, in outer space and in geological formations, these questions of molecular structure are also fundamental in related fields such as biology, geology, aeronomy, materials science and engineering.

John Pople took, as the major scientific challenge of his life, the understanding and prediction of molecular structure. He developed the methodology, provided the understandings, pointed out the appropriate computational approaches and did the technological spade-work to make such calculations available to all chemists. In the 1960s, he completed the first in a series of complex and accurate computer programs to be made available to the broad chemical community and to permit them to calculate, rather than to measure, how molecules are shaped and what properties they have.

Pople's deep insight extended beyond the purely scientific realm: he understood the importance of computers, and foresaw that they would not always be the hulking behemoths used to do computation in the 1950s. Indeed, the series of programs that Pople, and later his students and collaborators, have provided are available on computers of various sizes, from laptop to central processor. Pople founded two software companies in order to make these programs available to scientists seeking to understand and to control molecular processes. These companies were among the very first successful commercial ventures in computational chemistry.

John Anthony Pople was born in Burnham-on-Sea, in Somerset, in 1925. He attended Bristol Grammar School, and won a maths scholarship to Trinity College, Cambridge, in 1943. At the end of the Second World War, he worked temporarily for the Bristol Aeroplane Company, but returned to Cambridge in 1947. During those immediate postwar years, Cambridge was renewing its great accomplishments in the sciences. Pople completed his doctoral thesis entitled, simply, "Water", with the theoretical chemist Sir John Lennard-Jones.

Pople was trained as a mathematician. He never took a course in chemistry. Indeed, the American Chemical Society initially refused his application for membership because of his lack of chemical education. His application of mathematics to chemical problems earned him the Nobel Prize in Chemistry in 1988.

Pople moved to the United States following a period as head of Basic Physics at the National Physical Laboratory, Teddington. His move to the United States in 1964 came in the middle of the "brain drain." Indeed, one of the London dailies headlined his move with the quote, "Another Brain down the Drain."

His first research position in the United States was at Carnegie Mellon University, in Pittsburgh, where his original computer codes were completed. At Carnegie Mellon, Pople built a strong group of researchers and students who worked together on the actual invention of methods and writing of codes to permit computers to do chemistry. Pople's former students have started half a dozen successful businesses that have brought these quantum chemistry computation capabilities to the scientists and engineers of the world.

After two decades in Pittsburgh, Pople moved to Northwestern University, in Evanston, Chicago. There he built a new set of research interests, collaborations, capabilities, and students. His active research continued until his last illness, just a few months ago.

Pople was an enormously articulate man with a compelling voice and a direct manner. He had a dry and wonderful sense of humour and was a treasured friend to countless chemists worldwide. One of his former colleagues at Carnegie Mellon recalls Pople's lying on the floor to talk to a two-year old child "at the same level".

While at Cambridge, Pople took up the piano - literally. He had an old piano moved to his room at the top of a long staircase. There he would practise late at night. The resulting clamour caused his neighbor, the famous philosopher Wittgenstein, to pack up and leave. Pople's piano teacher Joy Bowers in 1952 became his wife. His marriage was a constant source of love, joy and inspiration until her death two years ago.

One of the nominations for Pople's Nobel Prize stated that, "by making it possible to determine chemical structure and properties using computation, Pople has changed the science of chemistry in a fundamental way and has empowered deeper understanding of the world for all of science and technology".

Mark Ratner