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Compact and accurate wave functions can be constructed by quantum Monte Carlo methods. Typically, these wave functions consist of a sum of a small number of Slater determinants multiplied by a Jastrow factor. In this paper we study the…

Condensed Matter · Physics 2009-10-30 Chien-Jung Huang , C. J. Umrigar , M. P. Nightingale

The quantum Monte Carlo (QMC) is one of the most promising many-body electronic structure approaches. It employs stochastic techniques for solving the stationary Schr\" odinger equation and for evaluation of expectation values. The key…

Other Condensed Matter · Physics 2007-12-20 Michal Bajdich

Quantum Monte Carlo (QMC) can play a very important role in generating accurate data needed for constructing potential energy surfaces. We argue that QMC has advantages in terms of a smaller systematic bias and an ability to cover phase…

Materials Science · Physics 2024-05-02 David M. Ceperley , Scott Jensen , Yubo Yang , Hongwei Niu , Carlo Pierleoni , Markus Holzmann

We employ quantum Monte Carlo to obtain chemically accurate vertical and adiabatic excitation energies, and equilibrium excited-state structures for the small, yet challenging, formaldehyde and thioformaldehyde molecules. A key ingredient…

Computational Physics · Physics 2019-08-02 Monika Dash , Jonas Feldt , Saverio Moroni , Anthony Scemama , Claudia Filippi

Quantum computation of vibrational properties of molecules is a promising platform to obtain computational advantages for computational chemistry. However, fault-tolerant quantum computations of vibrational properties remain a relatively…

The computation of vibrational spectra of diatomic molecules through the exact diagonalization of algebraically determined matrixes based on powers of Morse coordinates is made substantially more efficient by choosing a properly adapted…

Chemical Physics · Physics 2016-09-28 Andrea Bordoni , Nicola Manini

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…

Computational Physics · Physics 2016-09-08 Mark Dewing

This topical review describes the methodology of continuum variational and diffusion quantum Monte Carlo calculations. These stochastic methods are based on many-body wave functions and are capable of achieving very high accuracy. The…

Materials Science · Physics 2010-02-11 R. J. Needs , M. D. Towler , N. D. Drummond , P. Lopez Rios

Ab initio quantum Monte Carlo (QMC) is a state-of-the-art numerical approach for evaluating accurate expectation values of many-body wavefunctions. However, one of the major drawbacks that still hinders widespread QMC applications is the…

Materials Science · Physics 2024-07-17 Kousuke Nakano , Michele Casula , Giacomo Tenti

Quantum computers are ideal for solving chemistry problems due to their polynomial scaling with system size in contrast to classical computers which scale exponentially. Until now molecular energy calculations using quantum computing…

Quantum Physics · Physics 2019-08-15 Alexander Teplukhin , Brian K. Kendrick , Dmitri Babikov

This review covers applications of quantum Monte Carlo methods to quantum mechanical problems in the study of electronic and atomic structure, as well as applications to statistical mechanical problems both of static and dynamic nature. The…

chem-ph · Physics 2016-10-26 M. P. Nightingale , C. J. Umrigar

In the regime where traditional approaches to electronic structure cannot afford to achieve accurate energy differences via exhaustive wave function flexibility, rigorous approaches to balancing different states' accuracies become…

Chemical Physics · Physics 2017-11-22 Paul J. Robinson , Sergio D. Pineda Flores , Eric Neuscamman

We present a quantum algorithm for calculating the vibronic spectrum of a molecule, a useful but classically hard problem in chemistry. We show several advantages over previous quantum approaches: vibrational anharmonicity is naturally…

Quantum Physics · Physics 2019-08-02 Nicolas P. D. Sawaya , Joonsuk Huh

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

Quantum Monte Carlo (QMC) methods such as variational Monte Carlo and fixed node diffusion Monte Carlo depend heavily on the quality of the trial wave function. Although Slater-Jastrow wave functions are the most commonly used variational…

Materials Science · Physics 2015-05-28 Bryan K. Clark , Miguel A. Morales , Jeremy McMinis , Jeongnim Kim , Gustavo E. Scuseria

Anharmonic vibrational calculations can already be computationally demanding for relatively small molecules. The main bottlenecks lie in the construction of the potential energy surface and in the size of the excitation space in the…

Chemical Physics · Physics 2016-05-05 Pawel T. Panek , Christoph R. Jacob

The behavior of polyatomic molecules around their equilibrium positions can be regarded as quantum coupled anharmonic oscillators. Solving the corresponding Schr\"odinger equations can interpret or predict experimental spectra of molecules.…

Chemical Physics · Physics 2024-07-10 Qi Zhang , Rui-Si Wang , Lei Wang

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

Accurate simulations of vibrational molecular spectra are expensive on conventional computers. Compared to the electronic structure problem, the vibrational structure problem with quantum computers is less investigated. In this work we…

Within Full Configuration Interaction Quantum Monte Carlo, we investigate how the statistical error behaves as a function of the parameters which control the stochastic sampling. We define the inefficiency as a measure of the statistical…

Chemical Physics · Physics 2016-03-15 W. A. Vigor , J. S. Spencer , M. J. Bearpark , A. J. W. Thom