Benchmarking the pseudopotential and fixed-node approximations in diffusion Monte Carlo calculations of molecules and solids

Article

关键词: HARTREE-FOCK PSEUDOPOTENTIALS;    EFFECTIVE CORE POTENTIALS;    DISSOCIATION-ENERGY;    GROUND-STATE;    DIATOMIC-MOLECULES;    WAVE-FUNCTIONS;    QUANTUM;    SPECTROSCOPY;    SIMULATIONS;    SYSTEMS;   

DOI  :  10.1103/PhysRevB.93.094111

来源: SCIE

【 摘 要 】

We performed diffusion Monte Carlo (DMC) calculations of the spectroscopic properties of a large set of molecules, assessing the effect of different approximations. In systems containing elements with large atomic numbers, we show that the errors associated with the use of nonlocal mean-field-based pseudopotentials in DMC calculations can be significant and may surpass the fixed-node error. We suggest practical guidelines for reducing these pseudopotential errors, which allow us to obtain DMC-computed spectroscopic parameters of molecules and equation of state properties of solids in excellent agreement with experiment.

【 授权许可】

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