English
Related papers

Related papers: Inhomogeneous backflow transformations in quantum …

200 papers

Variational Monte Carlo and Green's function Monte Carlo are powerful tools for calculations of properties of light nuclei using realistic two-nucleon and three-nucleon potentials. Recently the GFMC method has been extended to multiple…

Nuclear Theory · Physics 2009-11-10 Steven C. Pieper

The variational and diffusion quantum Monte Carlo methods are used to calculate the correlation energy of the paramagnetic three-dimensional homogeneous electron gas at intermediate to high density. Ground state energies in finite cells are…

Strongly Correlated Electrons · Physics 2023-03-29 Sam Azadi , N. D. Drummond , S. M. Vinko

We investigate pfaffian trial wave functions with singlet and triplet pair orbitals by quantum Monte Carlo methods. We present mathematical identities and the key algebraic properties necessary for efficient evaluation of pfaffians.…

Other Condensed Matter · Physics 2013-05-29 M. Bajdich , L. Mitas , L. K. Wagner , K. E. Schmidt

All-electron variational and diffusion quantum Monte Carlo calculations of the ground state energies of the first row atoms (Li to Ne) are reported. We use trial wavefunctions of four types: single determinant Slater-Jastrow wavefunctions;…

Materials Science · Physics 2010-11-22 Matthew Brown , John Robert Trail , Pablo Lopez Rios , Richard Needs

In Paper by Titarchuk & Shrader the general formulation and results for photon reprocessing (downscattering) that included recoil and Comptonization effects due to divergence of the flow were presented. Here we show the Monte Carlo (MC)…

Astrophysics · Physics 2008-11-26 Philippe Laurent , Lev Titarchuk

Atomic force calculations within the variational and diffusion quantum Monte Carlo (VMC and DMC) methods are described. The advantages of calculating DMC forces with the "pure" rather than the "mixed" probability distribution are discussed.…

Materials Science · Physics 2010-02-15 A. Badinski , P. D. Haynes , J. R. Trail , R. J. Needs

Diffusion Monte Carlo (DMC) simulations for fermions are becoming the standard to provide high quality reference data in systems that are too large to be investigated via quantum chemical approaches. DMC with the fixed-node approximation…

Chemical Physics · Physics 2016-07-06 Andrea Zen , Sandro Sorella , Michael J. Gillan , Angelos Michaelides , Dario Alfè

Quantum backflow is a counterintuitive effect in which the probability density of a free particle moves in the direction opposite to the particle's momentum. If the particle is electrically charged, then the effect can be viewed as the…

Quantum Physics · Physics 2024-03-05 Arseni Goussev , Jaewoo Joo

The Monte Carlo Hamiltonian method developed recently allows to investigate ground state and low-lying excited states of a quantum system, using Monte Carlo algorithm with importance sampling. However, conventional MC algorithm has some…

High Energy Physics - Lattice · Physics 2018-01-17 Xiang-Qian Luo , Xiao-Ni Cheng , Helmut Kroger

Quantum Monte Carlo methods provide in principle an accurate treatment of the many-body problem of the ground and excited states of condensed systems. In practice, however, uncontrolled errors such as those arising from the fixed-node and…

Materials Science · Physics 2012-03-27 William W. Tipton , Neil D. Drummond , Richard G. Hennig

A theoretical study is reported of the molecular-to-atomic transition in solid hydrogen at high pressure. We use the diffusion quantum Monte Carlo method to calculate the static lattice energies of the competing phases and a…

Materials Science · Physics 2014-04-23 Sam Azadi , Bartomeu Monserrat , W. M. C. Foulkes , R. J. Needs

A self-contained and tutorial presentation of the diffusion Monte Carlo method for determining the ground state energy and wave function of quantum systems is provided. First, the theoretical basis of the method is derived and then a…

Computational Physics · Physics 2009-10-30 Ioan Kosztin , Byron Faber , Klaus Schulten

We report variational and diffusion Quantum Monte Carlo ground-state energies of the three-dimensional electron gas using a model periodic Coulomb interaction and backflow corrections for N=54, 102, 178, and 226 electrons. We remove…

Materials Science · Physics 2010-01-28 I. G. Gurtubay , R. Gaudoin , J. M. Pitarke

We demonstrate a scaling method for non-Markovian Monte Carlo wave-function simulations used to study open quantum systems weakly coupled to their environments. We derive a scaling equation, from which the result for the expectation values…

Quantum Physics · Physics 2009-11-10 J. Piilo , S. Maniscalco , A. Messina , F. Petruccione

We present a technique for optimizing hundreds of thousands of variational parameters in variational quantum Monte Carlo. By introducing iterative Krylov subspace solvers and by multiplying by the Hamiltonian and overlap matrices as they…

Strongly Correlated Electrons · Physics 2013-05-30 Eric Neuscamman , C. J. Umrigar , Garnet Kin-Lic Chan

A paramount goal in the field of nuclear physics is to unify ab-initio treatments of bound and unbound states. The position-space quantum Monte Carlo (QMC) methods have a long history of successful bound state calculations in light systems…

Nuclear Theory · Physics 2023-08-29 Abraham R. Flores , Kenneth M. Nollett

Accurate ab initio calculations are of fundamental importance in physics, chemistry, biology, and materials science, which have witnessed rapid development in the last couple of years with the help of machine learning computational…

Chemical Physics · Physics 2022-10-27 Yubing Qian , Weizhong Fu , Weiluo Ren , Ji Chen

Quantum Monte Carlo (QMC) methods are some of the most accurate methods for simulating correlated electronic systems. We investigate the compatibility, strengths and weaknesses of two such methods, namely, diffusion Monte Carlo (DMC) and…

Computational Physics · Physics 2020-10-14 Fionn D. Malone , Anouar Benali , Miguel A. Morales , Michel Caffarel , P. R. C. Kent , Luke Shulenburger

Monte Carlo evaluation is used to calculate heavy-ion elastic scattering including the center-of-mass correction and the Coulomb interaction.Angular distributions are presented for a number of nuclear pairs over a wide energy range using…

Nuclear Theory · Physics 2015-06-04 W. R. Gibbs , Jean-Pierre Dedonder

We investigate the inclusion of variable spins in electronic structure quantum Monte Carlo, with a focus on diffusion Monte Carlo with Hamiltonians that include spin-orbit interactions. Following our previous introduction of fixed-phase…

Computational Physics · Physics 2016-07-27 Cody A. Melton , M. Chandler Bennett , Lubos Mitas