Na8和Na20熔融的无轨道分子动力学模拟：分步熔融
Orbital-Free Molecular Dynamics Simulations of Melting in Na8 and Na20: Melting in Steps
摘要：
熔融的Na 8和Na 20的转变进行了研究从头算恒定能量分子动力学模拟，使用的Car-Parrinello方法的一个变体，采用明确的电子动能功能的密度，从而避免使用单粒子轨道。几个熔化指标进行评估，以确定各种过渡的性质，并与其他模拟。Na 8和Na 20两者在宽的温度范围内熔化。对于Na 8，观察到转变开始于约。110 K，在刚性相和涉及基态结构的不同置换异构体之间的异构化的相之间。“液体”阶段完全建立在大约。22万对于Na 2 O，观察到两个转变：第一个，在约100 ° C。110 K，与那些置换异构体之间的异构化转变的基态结构，这是通过交换的表面原子的位置获得的;第二，在约。160 K，涉及从基态异构体到一组新的异构体与表面熔融的结构转变。该集群是完全“液体”在约。22万
英文摘要：
The melting-like transitions of Na8 and Na20 are investigated by ab initio constant energy molecular dynamics simulations, using a variant of the Car-Parrinello method which employs an explicit electronic kinetic energy functional of the density, thus avoiding the use of one-particle orbitals. Several melting indicators are evaluated in order to determine the nature of the various transitions, and compared with other simulations. Both Na8 and Na20 melt over a wide temperature range. For Na8, a transition is observed to begin at approx. 110 K, between a rigid phase and a phase involving isomerizations between the different permutational isomers of the ground state structure. The ``liquid'' phase is completely established at approx. 220 K. For Na20, two transitions are observed: the first, at approx. 110 K, is associated with isomerization transitions between those permutational isomers of the ground state structure which are obtained by interchanging the positions of the surface-like atoms; the second, at approx. 160 K, involves a structural transition from the ground state isomer to a new set of isomers with the surface molten. The cluster is completely ``liquid'' at approx. 220 K.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
