New methods for Quantum Chemistry Andrew J. Millis, Columbia University, DMR 1006282

1. New methods for Quantum ChemistryAndrew J. Millis, Columbia University, DMR 1006282 The behavior of strongly interacting electrons is a grand challenge problem of broad scientific importance. `Dynamical mean field theory’ (DMFT), a technique widely used to treat the correlated electron materials of condensed matter physics, may be useful in quantum chemistry. For a standard quantum chemical test-bed system, DMFT provides energies competitive with the state of the art quantum chemical techniques, in the strong correlation regime (distances greater than or equal to minimum in energy curve). In the weak correlation (short bond) limit, coupled cluster methods are superior. Phys. Rev. Lett. 106 096402 (2011) Solid black line: best Dynamical Mean Field energy of H50 molecule compared to numerically exact answer (DMRG, open circles) and three standard quantum chemical approximations. Inset: relative errors of the methods

2. New methods for Quantum ChemistryAndrew J. Millis, Columbia University, DMR1006282 Broader impacts: --If successful, the research program begun with PRL 106 096402 will lead to new methods for studying excitation spectra, bond-breaking and transition metal complexes, as well as to new insights into real-material properties of condensed matter systems. --A collaboration (supported by DOE CMCSN grant and involving physicists, chemists and materials scientists) has now been started to explore these issues. --A key role is played by an outstanding graduate student, Ms Nan Lin, to whose training the project contributes. Other activities: The PI is co-organizer of 2012 Les Houches Summer school on Nonequilibrium quantum field theory. . The new methods enable computation of excitation spectra as well as energies