title: Efficient quantum monte carlo energies for molecular dynamics simulations.
abstract: A method is presented to treat electrons within the many-body quantum Monte Carlo (QMC) approach "on-the-fly" throughout a molecular dynamics (MD) simulation. Our approach leverages the large (10-100) ratio of the QMC electron to MD ion motion to couple the stochastic, imaginary-time electronic and real-time ionic trajectories. This continuous evolution of the QMC electrons results in highly accurate total energies for the full dynamical trajectory at a fraction of the cost of conventional, discrete sampling. We show that this can be achieved efficiently for both ground and excited states with only a modest overhead to an ab initio MD method. The accuracy of this dynamical QMC approach is demonstrated for a variety of systems, phases, and properties, including optical gaps of hot silicon quantum dots, dissociation energy of a single water molecule, and heat of vaporization of liquid water.
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue L-415, Livermore, California 94550, USA.
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Grossman
authors.forename: Lubos
authors.initials: L
authors.lastname: Mitas