TY - JOUR
T1 - Beyond the Born-Oppenheimer approximation with quantum Monte Carlo methods
AU - Tubman, Norm M.
AU - Kylänpää, Ilkka
AU - Hammes-Schiffer, Sharon
AU - Ceperley, David M.
N1 - Publisher Copyright:
© 2014 American Physical Society.
PY - 2014/10/21
Y1 - 2014/10/21
N2 - In this work we develop tools that enable the study of nonadiabatic 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 clamped ions and quantum nuclei. We explicitly calculate the ground-state energies of H2, LiH, H2O, 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.
AB - In this work we develop tools that enable the study of nonadiabatic 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 clamped ions and quantum nuclei. We explicitly calculate the ground-state energies of H2, LiH, H2O, 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.
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U2 - 10.1103/PhysRevA.90.042507
DO - 10.1103/PhysRevA.90.042507
M3 - Article
AN - SCOPUS:84908108526
SN - 1050-2947
VL - 90
JO - Physical Review A - Atomic, Molecular, and Optical Physics
JF - Physical Review A - Atomic, Molecular, and Optical Physics
IS - 4
M1 - 042507
ER -