The fixed-node quantum Monte Carlo (FNQMC) method is one of the most accuratemethods, with which Schrdinger equation could be solved including 80%--100% of thecorrelation energies for the molecules with 2-10 electrons...The fixed-node quantum Monte Carlo (FNQMC) method is one of the most accuratemethods, with which Schrdinger equation could be solved including 80%--100% of thecorrelation energies for the molecules with 2-10 electrons. However, the method hassome imperfections, i.e. (i) parametric numbers are too many to be optimized, (ii) the cuspcondition of the trial function cannot be satisfied.展开更多
In this paper, a novel exact fixed-node quantum Monte Carlo (EFNQMC) algorithm was proposed, which is a self-optimizing and self-improving procedure. In contrast to the previous EFNQMC method, the importance function ...In this paper, a novel exact fixed-node quantum Monte Carlo (EFNQMC) algorithm was proposed, which is a self-optimizing and self-improving procedure. In contrast to the previous EFNQMC method, the importance function of this method is optimized synchronistically in the diffusion procedure, but not before beginning the EFNQMC computation. In order to optimize the importance function, the improved steepest descent technique is used, in which the step size is automatically adjustable. The procedure is quasi-Newton type and converges super linearly. The present method also uses a novel trial function, which has correct electron-electron and electron-nucleus cusp conditions. The novel EFNQMC algorithm and the novel trial function are employed to calculate the energies of 1 1A 1 state of CH 2, 1A g state of C 8 and the ground-states of H 2, LiH, Li 2 and H 2O.展开更多
文摘The fixed-node quantum Monte Carlo (FNQMC) method is one of the most accuratemethods, with which Schrdinger equation could be solved including 80%--100% of thecorrelation energies for the molecules with 2-10 electrons. However, the method hassome imperfections, i.e. (i) parametric numbers are too many to be optimized, (ii) the cuspcondition of the trial function cannot be satisfied.
基金theNationalNaturalScienceFoundationofChina (No .2 0 1730 14 )andScienceFoundationofHunanProvince
文摘In this paper, a novel exact fixed-node quantum Monte Carlo (EFNQMC) algorithm was proposed, which is a self-optimizing and self-improving procedure. In contrast to the previous EFNQMC method, the importance function of this method is optimized synchronistically in the diffusion procedure, but not before beginning the EFNQMC computation. In order to optimize the importance function, the improved steepest descent technique is used, in which the step size is automatically adjustable. The procedure is quasi-Newton type and converges super linearly. The present method also uses a novel trial function, which has correct electron-electron and electron-nucleus cusp conditions. The novel EFNQMC algorithm and the novel trial function are employed to calculate the energies of 1 1A 1 state of CH 2, 1A g state of C 8 and the ground-states of H 2, LiH, Li 2 and H 2O.
