New method knocks out stubborn electron problem

A newly published article in Physical Review Letters eliminates one of the top unsolved theoretical problems in chemical physics as ranked by the National Research Council in 1995. Scientists now can more accurately predict the dynamic behavior of electrons in atoms and molecules in chemical reactions that govern a wide range of phenomena, including the fuel efficiency of combustion engines and the depletion of the atmospheric ozone. The paper by David Mazziotti , professor in chemistry at the University of Chicago, solves what specialists call the "N-representability problem." Robert Erdahl, a mathematician at Queens University in Canada and a leading authority on the N-representability problem, described Mazziotti's paper as "a striking advance," "an elegant theory," and "a remarkable achievement." Research on the theoretical foundations of the problem has advanced significantly along two important but separate lines of research for more than 60 years, Erdahl noted. "Work in both directions has proceeded independently even though it was widely understood that a unified approach was required to achieve a clear understanding. However, no one has been able to construct a theory where both paths enter in partnership. In his recent work Mazziotti has achieved precisely that." Molecules have anywhere from tens to thousands of electrons, and the computational complexity of simulating their behavior grows exponentially with the number of strongly correlated electrons, those whose motions are statistically linked to the motions of other electrons.