Monte Carlo methods: Application to hydrogen gas and hard spheres

Details Monte Carlo methods: Application to hydrogen gas and hard spheres Monte Carlo methods: Application to hydrogen gas and hard spheres

2000-12-14

arxiv.org/abs/physics/0012030v1

Physics

Computational Physics

97 pages, Ph. D. thesis, see also http://www.ncsa.uiuc.edu/Apps/CMP/dewing/thesis/index.html

Scientific paper

Quantum Monte Carlo (QMC) methods can very accurately compute ground state properties of quantum systems. We applied these methods to a system of boson hard spheres to get exact, infinite system size results for the ground state at several densities. Variational Monte Carlo (VMC) requires optimizing a parameterized wave function to find the minimum energy. We examine several techniques for optimizing VMC wave functions, focusing on the ability to optimize parameters appearing in the Slater determinant. The kinds of problems that can be simulated with Monte Carlo methods are expanded through the development of new algorithms for combining a QMC simulation of the electrons with a classical Monte Carlo simulation for the nuclei, which we call Coupled Electronic-Ionic Monte Carlo (CEIMC). The new CEIMC method is applied to a system of molecular hydrogen at temperatures ranging from 2800K to 4500K and densities from 0.25 to 0.46 g/cm**3. The challenges in constructing an efficient CEIMC simulation center mostly around the noisy results generated from the QMC computations of the electronic energy. The penalty method is a modification of the Metropolis method that can tolerate noise. An improved correlated sampling method, the two-sided energy difference method, is also presented as a method for reducing the noise.

Affiliated with

Also associated with

No associations

Rating

Monte Carlo methods: Application to hydrogen gas and hard spheres does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Monte Carlo methods: Application to hydrogen gas and hard spheres, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Monte Carlo methods: Application to hydrogen gas and hard spheres will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-510785