An efficient and accurate perturbative correction to initiator full configuration interaction quantum Monte Carlo

Abstract

We present a perturbative correction within initiator full configuration interaction quantum Monte Carlo (i-FCIQMC). In the existing i-FCIQMC algorithm, a significant number of spawned walkers are discarded due to the initiator criteria. Here we show that these discarded walkers have a form that allows calculation of a second-order Epstein-Nesbet correction, that may be accumulated in a trivial and inexpensive manner, yet substantially improves i-FCIQMC results. The correction is applied to the Hubbard model, the uniform electron gas and molecular systems.

5 pages, 1 figure, with Supplementary material also included

References in corpus (8)

• Heat-bath Configuration Interaction: An efficient selected CI algorithm inspired by heat-bath sampling
• Semistochastic Heat-bath Configuration Interaction method: selected configuration interaction with semistochastic perturbation theory
• Cheap and near exact CASSCF with large active spaces
• Excited states using semistochastic heat-bath configuration interaction
• Unbiased Reduced Density Matrices and Electronic Properties from Full Configuration Interaction Quantum Monte Carlo
• Excited States of Methylene, Polyenes, and Ozone from Heat-Bath Configuration Interaction
• Deterministic construction of nodal surfaces within quantum Monte Carlo: the case of FeS
• Multi-state effective Hamiltonian and size-consistency corrections in stochastic configuration interactions

Cited by in corpus (26)

• Modern Approaches to Exact Diagonalization and Selected Configuration Interaction with the Adaptive Sampling CI Method
• Reference Energies for Double Excitations
• The Ground State Electronic Energy of Benzene
• Selected configuration interaction dressed by perturbation
• NECI: N-Electron Configuration Interaction with emphasis on state-of-the-art stochastic methods
• Unbiasing the initiator approximation in Full Configuration Interaction Quantum Monte Carlo
• The Shape of Full Configuration Interaction to Come
• Many-Body Expanded Full Configuration Interaction. I. Weakly Correlated Regime
• The HANDE-QMC project: open-source stochastic quantum chemistry from the ground state up
• The Adaptive Shift Method in Full Configuration Interaction Quantum Monte Carlo: Development and Applications
• Efficient and Stochastic Multireference Perturbation Theory for Large Active Spaces within a Full Configuration Interaction Quantum Monte Carlo Framework
• Exciting determinants in Quantum Monte Carlo: Loading the dice with fast, low memory weights
• Preconditioning and perturbative estimators in full configuration interaction quantum Monte Carlo
• Excited-state diffusion Monte Carlo calculations: a simple and efficient two-determinant ansatz
• Multi-Reference Epstein-Nesbet Perturbation Theory with Density Matrix Renormalization Group Reference Wavefunction
• Fully quantum embedding with density functional theory for full configuration interaction quantum Monte Carlo
• Improved walker population control for full configuration interaction quantum Monte Carlo
• A hybrid approach to extending selected configuration interaction and full configuration interaction quantum Monte Carlo
• Stochastic differential equation approach to understanding the population control bias in full configuration interaction quantum Monte Carlo
• Accelerating convergence to the thermodynamic limit with twist angle selection applied to methods beyond many-body perturbation theory
• Fixed and partial-node approximations in Slater determinant space for molecules
• Beyond Walkers in Stochastic Quantum Chemistry: Reducing Error using Fast Randomized Iteration
• Full configuration interaction quantum Monte Carlo for coupled electron--boson systems and infinite spaces
• Full Configuration Interaction Excited-State Energies in Large Active Spaces from Subspace Iteration with Repeated Random Sparsification
• Coupled-cluster pairing models for radicals with strong correlations
• Improved Fast Randomized Iteration Approach to Full Configuration Interaction