Beyond the Born-Oppenheimer approximation with quantum Monte Carlo

Abstract

In this work we develop tools that enable the study of non-adiabatic effects with variational and diffusion Monte Carlo methods. We introduce a highly accurate wave function ansatz for electron-ion systems that can involve a combination of both fixed and quantum ions. We explicitly calculate the ground state energies of H${}_2$, LiH, H${}_2$O and FHF${}^{-}$ using fixed-node quantum Monte Carlo with wave function nodes that explicitly depend on the ion positions. The obtained energies implicitly include the effects arising from quantum nuclei and electron-nucleus coupling. We compare our results to the best theoretical and experimental results available and find excellent agreement.

arXiv comment6 Pages

References in corpus (9)

• Full optimization of Jastrow-Slater wave functions with application to the first-row atoms and homonuclear diatomic molecules
• Density matrix quantum Monte Carlo
• Energies of the first row atoms from quantum Monte Carlo
• Renyi Entropy of the Interacting Fermi Liquid
• Quantum Monte Carlo study of the first-row atoms and ions
• Finite temperature electronic simulations beyond the Born-Oppenheimer approximation
• Direct calculation of the Entanglement Spectrum in Quantum Monte Carlo with application to \textit{ab initio} Hamiltonians
• Finite temperature quantum statistics of H${}_3^{+}$ molecular ion
• Few-body reference data for multicomponent formalisms: Light nuclei molecules

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• Density functional theory beyond the Born-Oppenheimer approximation: accurate treatment of the ionic zero-point motion
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