Integration simulation

Gillan M J 1990 Path integral simulations of quantum systems Computer Modeling of Fluids and Polymers ed C R A Catlow et al (Dordrecht Kluwer)... 

It is necessary to sum over these pemuitations in a path integral simulation. (The same sum is needed for bosons, without the sign factor.) For femiions, odd pemuitations contribute with negative weight. Near-cancelling positive and negative pemuitations constitute a major practical problem [196]. 

R. E. Smith, Opus An Integrated Simulation Modelfor Transport of Nonpoint-Source Pollutants at the Field Scale, Vol. I, Documentation, USDA ARS-98, U.S. Dept, of Agriculture, Washington, D.C., 1992. 

Gao J, Wong K-Y, Major DT (2008) Combined QM/MM and path integral simulations of kinetic isotope effects in the proton transfer reaction between nitroethane and acetate ion in water. J Comput... 

Wang, Q. Johnson, J. K. Broughton, J. Q., Thermodynamic properties and phase equilibrium of fluid hydrogen from path integral simulations, Mol. Phys. 1996, 89, 1105-1119... 

There is considerable interest in the use of discretized path-integral simulations to calculate free energy differences or potentials of mean force using quantum statistical mechanics for many-body systems [140], The reader has already become familiar with this approach to simulating with classical systems in Chap. 7. The theoretical basis of such methods is the Feynmann path-integral representation [141], from which is derived the isomorphism between the equilibrium canonical ensemble of a... 

The Feynman-Hibbs and QFH potentials have been used extensively in simulations examining quantum effects in atomic and molecular fluids [12,15,25]. We note here that the centroid molecular dynamics method [54, 55] is related and is intermediate between a full path integral simulation and the Feynman-Hibbs approximation ... 

In this section, we will discuss some examples from the literature, in which the approximation methods derived in this chapter have been used. In several cases, the approximations have been compared with more-accurate path integral simulations to assess their validity. This is not meant as a full review rather, several case studies have been chosen to illustrate the tools we have developed. We will first look at simpler examples and then discuss water models and applications in enzyme kinetics. 

Modified force field models based on path integral simulations yield excellent agreement with experiment for thermodynamic properties. 

Morales, J. J. Singer, K., Path integral simulation of the free energy of Lennard-Jones neon, Mol. Phys. 1991, 73, 873-880... 

Liu, A. Beck, T. L., Determination of excess Gibbs free energy of quantum mixtures by MC path integral simulations, Mol. Phys. 1995, 86, 225-233... 

Stern, H. A. Berne, B. J., Quantum effects in liquid water path-integral simulations of a flexible and polarizable ab initio model, J. Chem. Phys. 2001,115, 7622... 

Predescu, C. Doll, J. D., Optimal series representations for numerical path integral simulations, J. Chem. Phys. 2003,117, 7448-7463... 

The centroid distribution function and the effective potential for the CMD simulation can be obtained through the path integral simulation method, - but... 

The next stage - from theory to practice in distributed system development - is to include logistics planning and material flow simulation (liquid or gas). Based on virtual reality simulation systems the integrated simulation system will combine the virtual reality and the material distribution network simulation. 

Dimian, A. C., Integrated Simulation and Design of Chemical Processes,... 

Room temperature simulations at the classical level yielded values of all AX° and quantities. Quantal results for G were also obtained from path integral simulations (in conjunction with Eq. 41) or semiclassical results based on spectral densities from the classical simulations [36]. The calculated classical G and 7. values and the AG° value were found to conform well to Eq. 112, and Gi t]) and Gf t]) functions were close to parabolic in form. Due to systematic deficiencies in the aqueous solvent model (a nonpolarizable force field and finite Coulombic cut-off, ca. 10 A), corrections to / were made on the basis of reference dielectric continuum models, and then G was corrected accordingly on the basis of Eq. 112. 

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