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We implement the phaseless auxiliary field quantum Monte Carlo method using the plane-wave based projector augmented wave method and explore the accuracy and the feasibility of applying our implementation to solids. We use a singular value…

Most non-relativistic interacting quantum many-body systems, such as atomic and molecular ensembles or materials, are naturally described in terms of continuous-space Hamiltonians. The simulation of their ground-state properties on digital…

Quantum Physics · Physics 2024-09-11 Friederike Metz , Gabriel Pescia , Giuseppe Carleo

We elucidate the origin of large differences (two-fold or more) in the fixed-node errors between the first- vs second-row systems for single-configuration trial wave functions in quantum Monte Carlo calculations. This significant difference…

Computational Physics · Physics 2015-06-17 Kevin M. Rasch , Shuming Hu , Lubos Mitas

We present a simple, general purpose, quantum Monte-Carlo algorithm for out-of-equilibrium interacting nanoelectronics systems. It allows one to systematically compute the expansion of any physical observable (such as current or density) in…

Mesoscale and Nanoscale Physics · Physics 2015-07-08 Rosario E. V. Profumo , Christoph Groth , Laura Messio , Olivier Parcollet , Xavier Waintal

We perform excited-state variational Monte Carlo and diffusion Monte Carlo calculations using a simple and efficient wave function ansatz. This ansatz follows the recent variation-after-response formalism, accurately approximating a…

Strongly Correlated Electrons · Physics 2018-12-24 Nick S. Blunt , Eric Neuscamman

In this study we present an optimization method based on the quantum Monte Carlo diagonalization for many-fermion systems. Using the Hubbard-Stratonovich transformation, employed to decompose the interactions in terms of auxiliary fields,…

Strongly Correlated Electrons · Physics 2009-11-13 Takashi Yanagisawa

We propose a novel algorithm for calculating the ground-state energy of quantum many-body systems by combining auxiliary-field quantum Monte Carlo (AFQMC) with tensor-train sketching. In AFQMC, a good trial wavefunction to guide the random…

Numerical Analysis · Mathematics 2026-02-17 Ziang Yu , Shiwei Zhang , Yuehaw Khoo

Quantum Monte Carlo methods are powerful numerical tools to accurately solve the Schr\"odinger equation for nuclear systems, a necessary step to describe the structure and reactions of nuclei and nucleonic matter starting from realistic…

Nuclear Theory · Physics 2020-05-01 Stefano Gandolfi , Diego Lonardoni , Alessandro Lovato , Maria Piarulli

A simple technique is proposed for numerically determining equilibrium ion distribution functions belonging to free energies of the Poisson-Boltzmann type. The central idea is to perform a conventional Monte-Carlo simulation using the free…

Soft Condensed Matter · Physics 2009-10-31 Markus Deserno

The essence of atomic structure theory, quantum chemistry, and computational materials science is solving the multi-electron stationary Schr\"odinger equation. The Quantum Monte Carlo-based neural network wave function method has surpassed…

Atomic Physics · Physics 2023-12-27 JinDe Liu , Chenglong Qin , Xi He , Gang Jiang

Quantum Monte Carlo methods are used to study a quantum phase transition in a 1D Hubbard model with a staggered ionic potential (D). Using recently formulated methods, the electronic polarization and localization are determined directly…

Strongly Correlated Electrons · Physics 2009-10-31 Tim Wilkens , Richard M. Martin

We reformulate the projected imaginary-time evolution of Full Configuration Interaction Quantum Monte Carlo in terms of a Lagrangian minimization. This naturally leads to the admission of polynomial complex wavefunction parameterizations,…

Strongly Correlated Electrons · Physics 2017-05-03 Lauretta R. Schwarz , A. Alavi , George H. Booth

The construction of trial wave functions based on neural networks combined with the variational Monte Carlo method is discussed. The mathematical formulation for representing quantum states as artificial neural networks is introduced. The…

Computational Physics · Physics 2026-05-19 William Freitas

We derive many-body single- and multi-reference wave functions for quantum Monte Carlo of periodic systems with an anti-symmetric portion that explicitly integrates over the Brillouin zone of one-particle Bloch states. The wave functions…

Strongly Correlated Electrons · Physics 2023-09-28 Lubos Mitas

We study one-dimensional (1D) and two-dimensional (2D) Helium atoms using a new time-dependent quantum Monte Carlo (TDQMC) method. The TDQMC method employs random walkers, with a separate guiding wave attached to each walker. The ground…

Atomic Physics · Physics 2025-02-07 I. P. Christov

Clusters of sizes ranging from two to five are studied by variational quantum Monte Carlo techniques. The clusters consist of Ar, Ne and hypothetical lighter (``$1 \over 2$-Ne") atoms. A general form of trial function is developed for which…

chem-ph · Physics 2009-10-22 Andrei Mushinski , M. P. Nightingale

Quantum Monte Carlo (QMC) is an advanced simulation methodology for studies of manybody quantum systems. In this review, we focus on the electronic structure QMC, i.e., methods relevant for systems described by the electron-ion…

Other Condensed Matter · Physics 2010-08-16 Michal Bajdich , Lubos Mitas

We present a systematically-improvable approach to core excitations in variational Monte Carlo. Building on recent work in excited-state-specific Monte Carlo, we show how a straightforward protocol, starting from a quantum chemistry guess,…

Chemical Physics · Physics 2020-10-28 Scott M. Garner , Eric Neuscamman

We investigate the use of different variational principles in quantum Monte Carlo, namely energy and variance minimization, prompted by the interest in the robust and accurate estimate of electronic excited states. For two prototypical,…

Chemical Physics · Physics 2021-11-19 Alice Cuzzocrea , Anthony Scemama , Wim J. Briels , Saverio Moroni , Claudia Filippi

Quantum Monte Carlo (QMC) methods represent a powerful family of computational techniques for tackling complex quantum many-body problems and performing calculations of stationary state properties. QMC is among the most accurate and…

Materials Science · Physics 2025-01-08 Alfonso Annarelli , Dario Alfè , Andrea Zen