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We suggest an efficient method to resolve electronic cusps in electronic structure calculations by using an effective transcorrelated Hamiltonian. This effective Hamiltonian takes a simple form for plane wave bases, containing up to…

Computational Physics · Physics 2018-02-14 Hongjun Luo , Ali Alavi

Quantum computing is emerging as a new computational paradigm with the potential to transform several research fields, including quantum chemistry. However, current hardware limitations (including limited coherence times, gate infidelities,…

In this paper, we propose a general analysis framework for inexact power iteration, which can be used to efficiently solve high dimensional eigenvalue problems arising from quantum many-body problems. Under the proposed framework, we…

Numerical Analysis · Mathematics 2018-06-29 Jianfeng Lu , Zhe Wang

Finding the ground state of a fermionic Hamiltonian using quantum Monte Carlo is a very difficult problem, due to the Fermi sign problem. While still scaling exponentially, full configuration-interaction Monte Carlo (FCI-QMC) mitigates some…

Computational Physics · Physics 2013-12-17 Michael H. Kolodrubetz , Bryan K. Clark

Variational quantum Monte Carlo (QMC) is an ab-initio method for solving the electronic Schr\"odinger equation that is exact in principle, but limited by the flexibility of the available ansatzes in practice. The recently introduced deep…

Computational Physics · Physics 2021-03-26 Zeno Schätzle , Jan Hermann , Frank Noé

An adaptation of the full configuration interaction quantum Monte Carlo (FCIQMC) method is presented, for correlated electron problems containing heavy elements and the presence of significant relativistic effects. The modified algorithm…

Chemical Physics · Physics 2020-10-26 Robert J. Anderson , George H. Booth

We present an approach to combining selected configuration interaction (SCI) and initiator full configuration interaction quantum Monte Carlo (i-FCIQMC). In the current i-FCIQMC scheme, the space of initiators is chosen dynamically by a…

Chemical Physics · Physics 2019-11-15 Nick S. Blunt

Computationally efficient numerical methods for high-order approximations of convolution integrals involving weakly singular kernels find many practical applications including those in the development of fast quadrature methods for…

Numerical Analysis · Mathematics 2018-10-10 Akash Anand , Awanish Kumar Tiwari

We present a reduced-scaling auxiliary-field quantum Monte Carlo (AFQMC) framework designed for large molecular systems and ensembles, with or without coupling to optical cavities. Our approach leverages the natural block sparsity of…

Chemical Physics · Physics 2026-02-03 Yu Zhang

For optimal accuracy, auxiliary-field quantum Monte Carlo (AFQMC) requires trial states consisting of multiple Slater determinants. We develop an efficient algorithm to select the determinants from an AFQMC random walk eliminating the need…

Chemical Physics · Physics 2025-07-08 Zoran Sukurma , Martin Schlipf , Georg Kresse

In common with many high-accuracy electronic structure methods, the initiator adaptation of full configuration interaction quantum Monte Carlo (i-FCIQMC) has difficulty treating realistic systems with large numbers of electrons. This…

Full configuration interaction quantum Monte Carlo (FCIQMC) is a stochastic approach for finding the ground state of a quantum many-body Hamiltonian. It is based on the dynamical evolution of a walker population in Hilbert space, which…

Quantum Gases · Physics 2020-11-04 Mingrui Yang , Elke Pahl , Joachim Brand

The semistochastic heat-bath configuration interaction (SHCI) method is a selected configuration interaction plus perturbation theory method that has provided near-full configuration interaction (FCI) levels of accuracy for many systems…

Chemical Physics · Physics 2021-11-30 Yuan Yao , Emmanuel Giner , Tyler A. Anderson , Julien Toulouse , C. J. Umrigar

This paper addresses the problem of frequency-domain inter-carrier interference (ICI) mitigation for differential orthogonal frequency-division multiplexing (OFDM) systems. The classical fractional fast Fourier transform (F-FFT), adopting…

Information Theory · Computer Science 2021-10-12 Jihui Qiu , Yuzhou Li , Yunlong Huang , Yimeng Wang , Lingyu Gu

We extend the scope of full configuration interaction quantum Monte Carlo (FCIQMC) to be applied to coupled fermion-boson hamiltonians, alleviating the a priori truncation in boson occupation which is necessary for many other wave function…

Strongly Correlated Electrons · Physics 2022-11-09 Robert J. Anderson , Charles C. J. Scott , George H. Booth

Population control is an essential component of any projector Monte Carlo algorithm. This control mechanism usually introduces a bias in the sampled quantities that is inversely proportional to the population size. In this paper, we…

Computational Physics · Physics 2021-04-28 Khaldoon Ghanem , Niklas Liebermann , Ali Alavi

We introduce an extension of the time-dependent variational Monte Carlo (tVMC) method that adaptively controls the expressivity of the variational quantum state during the simulation of the dynamics. This adaptive tVMC (atVMC) approach is…

Quantum Physics · Physics 2026-01-09 Raffaele Salioni , Rocco Martinazzo , Davide Emilio Galli , Christian Apostoli

Quantum simulation is a cornerstone application for quantum computing, yet standard methods face a trade-off between circuit depth and accuracy: Trotterization depth scales with the number of Hamiltonian terms $L$, while sampling-based…

Quantum Physics · Physics 2026-05-01 Sangjin Lee , Sangkook Choi

This work presents a method for the ab initio calculation of isotope shift in atoms and ions with one valence electron above closed shells. As a zero approximation we use relativistic Hartree-Fock and then calculate correlation corrections.…

Atomic Physics · Physics 2009-08-18 J. C. Berengut , V. A. Dzuba , V. V. Flambaum

We investigate the optimization of flexible tailored real-space Jastrow factors for use in the transcorrelated (TC) method in combination with highly accurate quantum chemistry methods such as initiator full configuration interaction…