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Simulation Of Electronic And Geometric Degrees Of Freedom Using A Kink-Based Path Integral Formulation: Application To Molecular Systems, Randall W. Hall
Simulation Of Electronic And Geometric Degrees Of Freedom Using A Kink-Based Path Integral Formulation: Application To Molecular Systems, Randall W. Hall
Randall W. Hall
A kink-based path integral method, previously applied to atomic systems, is modified and used to study molecular systems. The method allows the simultaneous evolution of atomic and electronic degrees of freedom. Results for CH4, NH3, and H2O demonstrate this method to be accurate for both geometries and energies. Comparison with DFT and MP2 level calculations show the path integral approach to produce energies in close agreement with MP2 energies and geometries in close agreement with both DFT and MP2 results.
An Adaptive, Kink-Based Approach To Path Integral Calculations, Randal W. Hall
An Adaptive, Kink-Based Approach To Path Integral Calculations, Randal W. Hall
Randall W. Hall
A kink-based expression for the canonical partition function is developed using Feynman’s path integral formulation of quantum mechanics and a discrete basis set. The approach is exact for a complete set of states. The method is tested on the 3×3 Hubbard model and overcomes the sign problem seen in traditional path integral studies of fermion systems. Kinks correspond to transitions between different N-electron states, much in the same manner as occurs in configuration interaction calculations in standard ab initio methods. The different N-electron states are updated, based on which states occur frequently during a Monte Carlo simulation, giving better estimates …
Simulation Of Electronic And Geometric Degrees Of Freedom Using A Kink-Based Path Integral Formulation: Application To Molecular Systems, Randall W. Hall
Simulation Of Electronic And Geometric Degrees Of Freedom Using A Kink-Based Path Integral Formulation: Application To Molecular Systems, Randall W. Hall
Randall W. Hall
A kink-based path integral method, previously applied to atomic systems, is modified and used to study molecular systems. The method allows the simultaneous evolution of atomic and electronic degrees of freedom. Results for CH4, NH3, and H2O demonstrate this method to be accurate for both geometries and energies. Comparison with DFT and MP2 level calculations show the path integral approach to produce energies in close agreement with MP2 energies and geometries in close agreement with both DFT and MP2 results.
An Adaptive, Kink-Based Approach To Path Integral Calculations, Randal W. Hall
An Adaptive, Kink-Based Approach To Path Integral Calculations, Randal W. Hall
Randall W. Hall
A kink-based expression for the canonical partition function is developed using Feynman’s path integral formulation of quantum mechanics and a discrete basis set. The approach is exact for a complete set of states. The method is tested on the 3×3 Hubbard model and overcomes the sign problem seen in traditional path integral studies of fermion systems. Kinks correspond to transitions between different N-electron states, much in the same manner as occurs in configuration interaction calculations in standard ab initio methods. The different N-electron states are updated, based on which states occur frequently during a Monte Carlo simulation, giving better estimates …