Extending J walking to quantum systems: Applications to atomic clusters

Frantz, D. D.; Freeman, D. L.; Doll, J. D.
October 1992
Journal of Chemical Physics;10/15/1992, Vol. 97 Issue 8, p5713
Academic Journal
The J-walking (or jump-walking) method is extended to quantum systems by incorporating it into the Fourier path integral Monte Carlo methodology. J walking can greatly reduce systematic errors due to quasiergodicity, or the incomplete sampling of configuration space in Monte Carlo simulations. As in the classical case, quantum J walking uses a jumping scheme to overcome configurational barriers. It couples the usual Metropolis sampling to a distribution generated at a higher temperature where the sampling is sufficiently ergodic. The J-walker distributions used in quantum J walking can be either quantum or classical, with classical distributions having the advantage of lower storage requirements, but the disadvantage of being slightly more computationally intensive and having a more limited useful temperature range. The basic techniques are illustrated first on a simple one-dimensional double well potential based on a quartic polynomial. The suitability of J walking for typical multidimensional quantum Monte Carlo systems is then shown by applying the method to a multiparticle cluster system consisting of rare gas atoms bound by pairwise Lennard-Jones potentials. Different degrees of quantum behavior are considered by examining both argon and neon clusters. Remarkable improvements in the convergence rate for the cluster energy and heat capacity, analogous to those found in classical systems, are found for temperatures near the cluster transition regions.


Related Articles

  • Interaction of HOCl with a chlorinated ice surface to produce molecular chlorine: An ab-initio study. Casassa, Silvia; Pisani, Cesare // Journal of Chemical Physics;6/8/2002, Vol. 116 Issue 22, p9856 

    The reaction between molecular HOC1 and a chlorinated surface of ice to produce molecular chlorine has been theoretically investigated. Ab initio quantum mechanical tools (GAUSSIAN 98 and EMBED01) have been used for this purpose, based on a molecular cluster and on an embedded cluster model,...

  • Alternative ansätze in single reference coupled-cluster theory. III. A critical analysis of different methods. Szalay, Péter G.; Nooijen, Marcel; Bartlett, Rodney J. // Journal of Chemical Physics;7/1/1995, Vol. 103 Issue 1, p281 

    There are several important formal requirements that should be satisfied if a quantum chemical method is to offer a widely applicable approach. This paper considers a variety of potential exponential ansätze, and assesses their attributes pertaining to different desiderata, in particular...

  • Quantum cluster equilibrium theory of liquids: Freezing of QCE/3-21G water to tetrakaidecahedral... Ludwig, R.; Weinhold, F. // Journal of Chemical Physics;1/1/1999, Vol. 110 Issue 1, p508 

    Reports on the extension of the Quantum Cluster Equilibrium (QCE) theory of liquid water to include large icelike clusters. Three- and four-coordinate icelike clusters; QCE liquid-solid transition; Sensitivity of the QCE results.

  • The quantum vibrational dynamics of Cl[sup -](H[sub 2]O)[sub n] clusters. Schenter, Gregory K.; Garrett, Bruce C.; Voth, Gregory A. // Journal of Chemical Physics;10/1/2000, Vol. 113 Issue 13 

    The centroid molecular dynamics technique is applied to the case of chloride-water clusters to estimate their finite temperature quantum vibrational structure. We employ the flexible RWK2 water potential [J. R. Reimers, R. O. Watts, and M. L. Klein, Chem. Phys. 64, 95 (1982)] and the...

  • Carbon clusters: The structure of C10 studied with configuration interaction methods. Liang, Congxin; Schaefer, Henry F. // Journal of Chemical Physics;12/15/1990, Vol. 93 Issue 12, p8844 

    The structure of the C10 carbon cluster is studied by ab initio quantum mechanical methods using self-consistent-field and configuration interaction theories. Three monocyclic and two linear structures are considered. It is found that all the monocyclic structures are considerably lower in...

  • Centroid path integral molecular dynamics simulation of lithium para-hydrogen clusters. Kinugawa, Kenichi; Moore, Preston B. // Journal of Chemical Physics;1/15/1997, Vol. 106 Issue 3, p1154 

    Investigates the real-time quantum dynamics of a series of lithium para-hydrogen clusters by means of normal mode centroid path integral molecular dynamics (NMCMD) simulation. Microcanocial and constant-temperature equations of motion for NMCMD sumilations using the Nose-Hoover chain...

  • Linear response functions for coupled cluster/molecular mechanics including polarization interactions. Kongsted, Jacob; Osted, Anders; Mikkelsen, Kurt V.; Christiansen, Ove // Journal of Chemical Physics;1/22/2003, Vol. 118 Issue 4, p1620 

    We present the first implementation of linear response theory for the coupled cluster/molecular mechanics (CC/MM) method. This model introduces polarization effects into a quantum mechanical/molecular mechanical (QM/MM) framework using a self-consistent procedure while electrostatic effects are...

  • Model calculations of resonant vibration to vibration transition probabilities in clusters. Herman, Michael F. // Journal of Chemical Physics;9/22/1998, Vol. 109 Issue 12, p4726 

    Presents the results of the calculated resonant transfer probability of vibrational energy in clusters of identical molecules using quantum mechanics. Propagation of the wave function for the vibrational degrees of freedom of the molecules; Presence of long coherence time for vibrational...

  • Intramolecular vibrational redistribution and fragmentation dynamics of I[sub 2]...Ne[sub n]... Alberti, S. Fernandez; Halberstadt, N.; Beswick, J.A.; Bastida, A.; Zuniga, J.; Requena, A. // Journal of Chemical Physics;7/1/1999, Vol. 111 Issue 1, p239 

    Studies the intramolecular vibrational energy redistribution and fragmentation dynamics in I[sub2](B,v=22)...Nen(n=2-6) and I[sub2](B,v=21)...Nen(n=2-5) clusters using hybrid quantum/classical techniques. Use of vibrational version of molecular dynamics with quantum transitions; Representation...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics