Kalikka J, Konstantinou K, Akola J, Jones R O
Computational Physics Laboratory, Tampere University, FI-33014 Tampere, Finland.
Department of Physics, NTNU Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
J Phys Condens Matter. 2021 Aug 20;33(44). doi: 10.1088/1361-648X/ac1aa3.
Molecular dynamics simulations using a density functional description of energies and forces have been carried out for a model of an as-deposited (AD) surface of amorphous selenium. The deposition model assumed the annealing (at 400 K) of layers of randomly located single atoms, followed by compression to the density used in earlier melt-quenched (MQ) simulations of amorphous Se, and by further annealing. The AD and MQ structures are predominantly twofold coordinated and similar, for example in the pair distribution functions, with notable differences: the AD structures have more defects (atoms with one and three neighbours), and the ring distributions differ. These differences are also reflected in the electronic structures of the AD and MQ samples, where the increased presence of defects in the former influences the Bader charges and the edge states of the band gap. The dominance of rings found in a previous simulation of AD structures is not found.
使用能量和力的密度泛函描述进行了分子动力学模拟，对象是非晶态硒沉积态（AD）表面的模型。沉积模型假设对随机定位的单个原子层进行退火（在400K），然后压缩至早期非晶态硒熔体淬火（MQ）模拟中使用的密度，并进一步退火。AD和MQ结构主要是二重配位且相似，例如在对分布函数方面，但存在显著差异：AD结构有更多缺陷（具有一个和三个邻居的原子），并且环分布不同。这些差异也反映在AD和MQ样品的电子结构中，其中前者中缺陷的增加影响了巴德电荷和带隙的边缘态。在先前对AD结构的模拟中发现的环的主导地位并未出现。
