The studies on the theories and calculation method of low-energy electron scattering(LEES) in solids have provided a basis for the development of electron microscopy andelectron beam lithography. In the energy region ...The studies on the theories and calculation method of low-energy electron scattering(LEES) in solids have provided a basis for the development of electron microscopy andelectron beam lithography. In the energy region where the primary energy of incident elec-展开更多
高能电子和物质相互作用是一个级联簇射 (shower)物理过程 .空间飞行器防护系统就是利用这一原理 ,通过宇宙中的电子在飞行器中产生的 shower电子 ,来了解其中半导体器件的有关信息 .该文利用 Monte Carlo方法 ,采用 PENEL OPE(Penetrat...高能电子和物质相互作用是一个级联簇射 (shower)物理过程 .空间飞行器防护系统就是利用这一原理 ,通过宇宙中的电子在飞行器中产生的 shower电子 ,来了解其中半导体器件的有关信息 .该文利用 Monte Carlo方法 ,采用 PENEL OPE(Penetration and Energy L oss of Positrons and Electrons)软件包 ,对电子在飞行器中的运动过程进行模拟 ,给出球壳和半导体材料中的能量沉积分布 。展开更多
In this paper, a novel method for fixed-node quantum Monte Carlo is given. We have derived an expansion of the eigenvalue of the energy for a system and proved that the value of the energy calculated using the tradit...In this paper, a novel method for fixed-node quantum Monte Carlo is given. We have derived an expansion of the eigenvalue of the energy for a system and proved that the value of the energy calculated using the traditional fixed-node quantum Monte Carlo method is only the zero order approximation of the eigenvalue of the energy. But when using our novel method, in the case of only increasing less computing amounts (<1%), we can obtain conveniently the first order approximation, second order approximation, and so on. We have calculated the values of the zero, first and second approximation (0, 1 and 2) of the energies of 11A1 state of CH2, 1Ag (C4h, acet) state of C8 and the ground-state of H2O using this novel method. The results indicate that for 11A1 state of CH2, 1Ag (C4h, acet) state of C8 and the ground-state of H2O it needs only the second order approximation to obtain electronic correlation energy with over 97%. This demonstrates that this novel method is very excellent in both the computing accuracy and the amount of calculation required.展开更多
文摘The studies on the theories and calculation method of low-energy electron scattering(LEES) in solids have provided a basis for the development of electron microscopy andelectron beam lithography. In the energy region where the primary energy of incident elec-
文摘高能电子和物质相互作用是一个级联簇射 (shower)物理过程 .空间飞行器防护系统就是利用这一原理 ,通过宇宙中的电子在飞行器中产生的 shower电子 ,来了解其中半导体器件的有关信息 .该文利用 Monte Carlo方法 ,采用 PENEL OPE(Penetration and Energy L oss of Positrons and Electrons)软件包 ,对电子在飞行器中的运动过程进行模拟 ,给出球壳和半导体材料中的能量沉积分布 。
基金This research work was supported by the National Natural Science Foundation of China(No.29773036)Science Foundation of the Education Committee of Hunan.
文摘In this paper, a novel method for fixed-node quantum Monte Carlo is given. We have derived an expansion of the eigenvalue of the energy for a system and proved that the value of the energy calculated using the traditional fixed-node quantum Monte Carlo method is only the zero order approximation of the eigenvalue of the energy. But when using our novel method, in the case of only increasing less computing amounts (<1%), we can obtain conveniently the first order approximation, second order approximation, and so on. We have calculated the values of the zero, first and second approximation (0, 1 and 2) of the energies of 11A1 state of CH2, 1Ag (C4h, acet) state of C8 and the ground-state of H2O using this novel method. The results indicate that for 11A1 state of CH2, 1Ag (C4h, acet) state of C8 and the ground-state of H2O it needs only the second order approximation to obtain electronic correlation energy with over 97%. This demonstrates that this novel method is very excellent in both the computing accuracy and the amount of calculation required.
