scholarly journals Twist-averaged boundary conditions in continuum quantum Monte Carlo algorithms

2001 ◽  
Vol 64 (1) ◽  
Author(s):  
C. Lin ◽  
F. H. Zong ◽  
D. M. Ceperley
Keyword(s):  
Monte Carlo ◽  
Boundary Conditions ◽  
Quantum Monte Carlo ◽  
Monte Carlo Algorithms

Engineering local optimality in quantum Monte Carlo algorithms

2007 ◽  
Vol 225 (2) ◽  
pp. 2249-2266 ◽  
Author(s):  
Lode Pollet ◽  
Kris Van Houcke ◽  
Stefan M.A. Rombouts
Keyword(s):  
Monte Carlo ◽  
Quantum Monte Carlo ◽  
Local Optimality ◽  
Monte Carlo Algorithms

MONTE CARLO DIAGONALIZATION OF VERY LARGE MATRICES: APPLICATION TO FERMION SYSTEMS

1992 ◽  
Vol 03 (01) ◽  
pp. 97-104 ◽  
Author(s):  
H. DE RAEDT ◽  
W. VON DER LINDEN
Keyword(s):  
Monte Carlo ◽  
Quantum Monte Carlo ◽  
General Feature ◽  
Degrees Of Freedom ◽  
Fundamental Problem ◽  
Simulation Methods ◽  
Fermion Systems ◽  
Monte Carlo Algorithms ◽  
Minus Sign ◽  
Sign Problem

All known Quantum-Monte-Carlo algorithms for fermions suffer from the so-called “minus-sign-problem” which is detrimental to the application of these simulation methods to fermion systems at very low temperatures and/or of very many lattice sites. We identify the origin of this fundamental problem, demonstrate that it is a very general feature, not necessarily related to the presence of fermionic degrees of freedom. We describe an novel algorithm which does not suffer from the minus-sign problem. Illustrative results for the two-dimensional Hubbard model are presented

scholarly journals Quantum Monte Carlo algorithms for electronic structure at the petascale; the Endstation project

2008 ◽  
Vol 125 ◽  
pp. 012057 ◽  
Author(s):  
K P Esler ◽  
J Kim ◽  
D M Ceperley ◽  
W Purwanto ◽  
E J Walter ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Electronic Structure ◽  
Quantum Monte Carlo ◽  
Monte Carlo Algorithms

Monte Carlo Algorithms for Moments of Transition Arrays

1988 ◽  
Vol 102 ◽  
pp. 79-81
Author(s):  
A. Goldberg ◽  
S.D. Bloom
Keyword(s):  
Monte Carlo ◽  
State Vector ◽  
Basis Vector ◽  
Collective State ◽  
Dispersion Characteristics ◽  
Dipole Strength ◽  
The Third ◽  
Monte Carlo Algorithms ◽  
Third Moment ◽  
Very High

AbstractClosed expressions for the first, second, and (in some cases) the third moment of atomic transition arrays now exist. Recently a method has been developed for getting to very high moments (up to the 12th and beyond) in cases where a “collective” state-vector (i.e. a state-vector containing the entire electric dipole strength) can be created from each eigenstate in the parent configuration. Both of these approaches give exact results. Herein we describe astatistical(or Monte Carlo) approach which requires onlyonerepresentative state-vector |RV> for the entire parent manifold to get estimates of transition moments of high order. The representation is achieved through the random amplitudes associated with each basis vector making up |RV>. This also gives rise to the dispersion characterizing the method, which has been applied to a system (in the M shell) with≈250,000 lines where we have calculated up to the 5th moment. It turns out that the dispersion in the moments decreases with the size of the manifold, making its application to very big systems statistically advantageous. A discussion of the method and these dispersion characteristics will be presented.

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