随着超级计算机硬件和数值算法迅速发展,使得目前利用密度泛函理论研究上千个原子体系的电子能带和结构等性质变得可行.数值原子轨道基组由于其基组较小和局域等特性,可以很好地与电子结构计算中的线性标度算法等的新算法结合,用来研究...随着超级计算机硬件和数值算法迅速发展,使得目前利用密度泛函理论研究上千个原子体系的电子能带和结构等性质变得可行.数值原子轨道基组由于其基组较小和局域等特性,可以很好地与电子结构计算中的线性标度算法等的新算法结合,用来研究较大尺寸的物理体系.本文详细介绍了一款中国科学技术大学量子信息重点实验室自主开发的基于数值原子轨道基组的第一性原理计算软件Atomic-orbital Based Ab-initio Computation at UStc.大量的测试结果表明:该软件具有很好的准确性和较高的并行效率,可以用于包含1000个原子左右的系统的电子结构和原子结构的研究以及分子动力学模拟计算.展开更多
The diffusion property of the intercalated species in the graphite materials is at the heart of the rate performance of graphite-based metal-ion secondary battery.Here we study the diffusion process of a AlCl_(4) mole...The diffusion property of the intercalated species in the graphite materials is at the heart of the rate performance of graphite-based metal-ion secondary battery.Here we study the diffusion process of a AlCl_(4) molecule within graphite—a key component of a recently reported aluminum ion battery with excellent performance—via molecular dynamics(MD)simulations.Both ab-initio MD(AIMD)and semiempirical tight-binding MD simulations show that the diffusion process of the intercalated AlCl_(4) molecule becomes rather inhomogeneous,when the simulation time exceeds approximately 100 picoseconds.Specifically,during its migration in between graphene layers,the intercalated AlCl_(4) molecule may become stagnant occasionally,and then recovers its normal(fast)diffusion behavior after halting for a while.When this phenomenon occurs,the linear relationship of the mean squared displacement(MSD)versus the duration time is not fulfilled.We interpret this peculiar behavior as a manifestation of inadequate sampling of rare event(the stagnation of the molecule),which does not yet appear in short-time MD simulations.We further check the influence of strains present in graphite intercalated compounds(GIC)on the diffusion properties of AlCl_(4),and find that their presence in general slows down the diffusion of the intercalated molecule,and is detrimental to the rate performance of the GIC-based battery.展开更多
文摘随着超级计算机硬件和数值算法迅速发展,使得目前利用密度泛函理论研究上千个原子体系的电子能带和结构等性质变得可行.数值原子轨道基组由于其基组较小和局域等特性,可以很好地与电子结构计算中的线性标度算法等的新算法结合,用来研究较大尺寸的物理体系.本文详细介绍了一款中国科学技术大学量子信息重点实验室自主开发的基于数值原子轨道基组的第一性原理计算软件Atomic-orbital Based Ab-initio Computation at UStc.大量的测试结果表明:该软件具有很好的准确性和较高的并行效率,可以用于包含1000个原子左右的系统的电子结构和原子结构的研究以及分子动力学模拟计算.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFB0201202)the National Natural Science Foundation of China(Grant Nos.11874335 and 11774327)。
文摘The diffusion property of the intercalated species in the graphite materials is at the heart of the rate performance of graphite-based metal-ion secondary battery.Here we study the diffusion process of a AlCl_(4) molecule within graphite—a key component of a recently reported aluminum ion battery with excellent performance—via molecular dynamics(MD)simulations.Both ab-initio MD(AIMD)and semiempirical tight-binding MD simulations show that the diffusion process of the intercalated AlCl_(4) molecule becomes rather inhomogeneous,when the simulation time exceeds approximately 100 picoseconds.Specifically,during its migration in between graphene layers,the intercalated AlCl_(4) molecule may become stagnant occasionally,and then recovers its normal(fast)diffusion behavior after halting for a while.When this phenomenon occurs,the linear relationship of the mean squared displacement(MSD)versus the duration time is not fulfilled.We interpret this peculiar behavior as a manifestation of inadequate sampling of rare event(the stagnation of the molecule),which does not yet appear in short-time MD simulations.We further check the influence of strains present in graphite intercalated compounds(GIC)on the diffusion properties of AlCl_(4),and find that their presence in general slows down the diffusion of the intercalated molecule,and is detrimental to the rate performance of the GIC-based battery.
