Jayant K. Singh

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We consider the accuracy of several methods for combining forward and reverse free-energy perturbation averages for two systems ͑labeled 0 and 1͒. The practice of direct averaging of these measurements is argued as not reliable. Instead, methods are considered of the form ␤(A 1 ϪA 0) ϭϪln͓͗w(u)exp(Ϫ␤u/2)͘ 0 /͗w(u)exp(ϩ␤u/2)͘ 1 ͔, where A is the free energy,(More)
Vapor–liquid interfacial tension of square-well ͑SW͒ fluids is calculated using three different methods viz., molecular dynamics ͑MD͒ with collision-based virial evaluation, Monte Carlo with virial computed by volume perturbation, and Binder's density-distribution method in conjunction with grand-canonical transition-matrix Monte Carlo ͑GC-TMMC͒. Three(More)
Free-energy simulation methods are applied toward the calculation of cluster integrals that appear in diagrammatic methods of statistical mechanics. In this approach, Monte Carlo sampling is performed on a number of molecules equal to the order of the integral, and configurations are weighted according to the absolute value of the integrand. An(More)
We use the Mayer sampling method, with both direct and overlap sampling, to calculate and compare classical virial coefficients up to B6 for various water models (SPC, SPC/E, MSPC/E, TIP3P, and TIP4P). The precision of the computed values ranges from 0.1% for B2 to an average of 25% for B6. When expressed in a form scaled by the critical properties, the(More)
An ab initio derived transferable polarizable force-field has been developed for Zinc sulphide (ZnS) nanoparticle (NP) and ZnS NP-PMMA nanocomposite. The structure and elastic constants of bulk ZnS using the new force-field are within a few percent of experimental observables. The new force-field show remarkable ability to reproduce structures and(More)
It is known that a horizontally vibrated binary mixture in a tapered and inclined channel segregates axially, with the two grains moving to the opposite ends of the channel. In general, the parameters that affect the segregation process include the vibration frequency and its amplitude, the constituents' mass and size, and the taper and inclination of the(More)
We examine a model system to study the effect of pressure on the surface tension of a vapor-liquid interface. The system is a two-component mixture of spheres interacting with the square-well (A-A) and hard-sphere (B-B) potentials and with unlike (A-B) interactions ranging (for different cases) from hard sphere to strongly attractive square well. The(More)
Grand-canonical transition-matrix Monte Carlo simulation is applied to analyze the effect of molecular association on the vapor –liquid coexistence and inter-facial behavior of square-well based dimerizing fluids. Finite-size scaling techniques are implemented in conjunction with histogram reweighting to determine the infinite-system surface tension from a(More)
Vapor-liquid interfacial properties of square-well associating fluids are studied via transition-matrix Monte Carlo simulation. Results for one-site and two-site association models are presented. Coexistence properties, surface tension, cluster distribution, density profile, and orientation profile are presented. Molecular association affects the(More)
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