scholarly journals Generalizing the self-healing diffusion Monte Carlo approach to finite temperature: A path for the optimization of low-energy many-body bases

2014 ◽  
Vol 140 (7) ◽  
pp. 074103 ◽  
Author(s):  
Fernando A. Reboredo ◽  
Jeongnim Kim
Keyword(s):  
Monte Carlo ◽  
Finite Temperature ◽  
Low Energy ◽  
The Self ◽  
Self Healing ◽  
Many Body ◽  
Diffusion Monte Carlo ◽  
Monte Carlo Approach

GLOBAL MINIMA FOR PdN (N = 5–80) CLUSTERS DESCRIBED BY SUTTON–CHEN POTENTIAL

2007 ◽  
Vol 18 (08) ◽  
pp. 1351-1359 ◽  
Author(s):  
HAYDAR ARSLAN
Keyword(s):  
Monte Carlo ◽  
Energy Surface ◽  
Central Atom ◽  
Low Energy ◽  
Global Minima ◽  
Many Body ◽  
Pd Clusters ◽  
Body Potential ◽  
Basin Hopping ◽  
Theoretical Results

The structure and energetics of Pd N (N = 5–80) clusters have been studied extensively by a Monte Carlo method based on Sutton–Chen many-body potential. The basin-hopping algorithm is used to find the low-energy minima on the potential energy surface for each nuclearity. A variety of structure types (icosahedral, decahedral and fcc closed-packed) are observed for Pd clusters. Some of the icosahedral global minima do not have a central atom. The resulting structures have been compared with the previous theoretical results.

scholarly journals QUANTUM MONTE CARLO METHODS FOR NUCLEI AT FINITE TEMPERATURE

2001 ◽  
Vol 15 (10n11) ◽  
pp. 1447-1462 ◽  
Author(s):  
Y. ALHASSID
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Methods ◽  
Finite Temperature ◽  
Quantum Monte Carlo ◽  
Configuration Spaces ◽  
Many Body ◽  
Level Densities ◽  
Sign Problem ◽  
Quantum Monte Carlo Methods ◽  
Nuclear Shell

We discuss finite temperature quantum Monte Carlo methods in the framework of the interacting nuclear shell model. The methods are based on a representation of the imaginary-time many-body propagator as a superposition of one-body propagators describing non-interacting fermions moving in fluctuating auxiliary fields. Fermionic Monte Carlo calculations have been limited by a "sign" problem. A practical solution in the nuclear case enables realistic calculations in much larger configuration spaces than can be solved by conventional methods. Good-sign interactions can be constructed for realistic estimates of certain nuclear properties. We present various applications of the methods for calculating collective properties and level densities.

scholarly journals A FOURTH ORDER DIFFUSION MONTE CARLO ALGORITHM FOR SOLVING QUANTUM MANY-BODY PROBLEMS

2001 ◽  
Vol 15 (10n11) ◽  
pp. 1752-1755 ◽  
Author(s):  
H. A. FORBERT ◽  
S. A. CHIN
Keyword(s):  
Monte Carlo ◽  
Fourth Order ◽  
Planck Equation ◽  
Monte Carlo Algorithm ◽  
Bulk Liquid ◽  
Many Body ◽  
Diffusion Monte Carlo ◽  
Step Size ◽  
Wide Range ◽  
Gaussian Random Walk

We derive a fourth-order diffusion Monte Carlo algorithm for solving quantum many-body problems. The method uses a factorization of the imaginary time propagator in terms of the usual local energy E and Langevin operators L as well as an additional pseudo-potential consisting of the double commutator [EL, [L, EL]]. A new factorization of the propagator of the Fokker-Planck equation enables us to implement the Langevin algorithm to the necessary fourth order. We achieve this by the addition of correction terms to the drift steps and the use of a position-dependent Gaussian random walk. We show that in the case of bulk liquid helium the systematic step size errors are indeed fourth order over a wide range of step sizes.

scholarly journals Permutation blocking path integral Monte Carlo approach to the uniform electron gas at finite temperature

2015 ◽  
Vol 143 (20) ◽  
pp. 204101 ◽  
Author(s):  
Tobias Dornheim ◽  
Tim Schoof ◽  
Simon Groth ◽  
Alexey Filinov ◽  
Michael Bonitz
Keyword(s):  
Monte Carlo ◽  
Path Integral ◽  
Finite Temperature ◽  
Electron Gas ◽  
Path Integral Monte Carlo ◽  
Monte Carlo Approach ◽  
Uniform Electron Gas
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