Vásquez-Pérez José Manuel, Gamboa Martínez Gabriel Ulises, Köster Andreas M, Calaminici Patrizia
Departamento de Química, CINVESTAV, Av. Instituto Politécnico Nacional 2508, AP 14-740, México DF 07000, Mexico.
J Chem Phys. 2009 Sep 28;131(12):124126. doi: 10.1063/1.3231134.
This work presents a density functional study of neutral, cationic, and anionic sodium cluster heptamers. The cluster structures were optimized with the local density approximation as well as with the generalized gradient approximation. For the neutral and cationic clusters new unexpected isomers are found closed in energy to the well known ground state structures. In the case of the neutral heptamer the new isomer was first noticed by inspection of a first-principles Born-Oppenheimer molecular dynamics (BOMD) simulations at 300 K. A structure alignment algorithm is presented which facilitates the discovery of new structures from such BOMD simulations. With this algorithm the structural evolution of the two low-lying isomers of the neutral, cationic, and anionic heptamer was analyzed at different temperatures. This work demonstrates the capability of reasonably long (approximately 100 ps) first-principles BOMD simulations to explore the potential energy landscape of metallic clusters.
本文展示了对中性、阳离子和阴离子钠簇七聚体的密度泛函研究。使用局域密度近似以及广义梯度近似对簇结构进行了优化。对于中性和阳离子簇，发现了与众所周知的基态结构能量相近的新的意外异构体。在中性七聚体的情况下，新异构体首先是通过在300 K下对第一性原理玻恩-奥本海默分子动力学（BOMD）模拟进行检查而被注意到的。提出了一种结构比对算法，该算法有助于从此类BOMD模拟中发现新结构。利用该算法，分析了中性、阳离子和阴离子七聚体的两种低能异构体在不同温度下的结构演化。这项工作证明了合理长时间（约100皮秒）的第一性原理BOMD模拟探索金属簇势能面的能力。
