Ab Initio Prediction of Amorphous B₈₄

Abstract

To explore the possible existence of boron clusters without carbon analogs, we study B(84) cluster as a prototypical system by ab initio calculations. Structures of several isomer forms of B(84) are optimized. Among these isomers, a group of amorphous (disordered) structures are found to be the most stable. Different from the high-symmetry isomers, the amorphous B(84) clusters are more stable than the fullerene B(80) in terms of cohesive energy per atom. These amorphous structures can be distinguished from other high-symmetry structures experimentally via, for example, infrared spectra. The radial and angular distribution functions of amorphous B(84) structures are more diffuse than those of high-symmetry structures. On the basis of these findings, we propose that amorphous structures may be generic for boron and dominate boron clusters in a range of cluster scale.

Possible mechanism of BN fullerene formation from a boron cluster: Density‐functional tight‐binding molecular dynamics simulations

“…During the simulation, the B atoms rapidly cohered to form a disordered aggregate within 2 ps, and then the aggregate underwent considerable structural deformation without disintegrating. Recent theoretical studies based on more sophisticated first‐principles electronic structure calculations found that medium‐sized B clusters consisting of several tens of B atoms do not have a strong structural preference compared with their BN and C counterparts, suggesting that medium‐sized B clusters favor amorphous structures . This was explained by the electronically frustrated nature of the B clusters originating from the unfilled sp 2 hybrid orbitals.…”

Indium coverage of the Si(111)- 7×3 -In surface

“…However, their In coverages and hence atomic configurations are still controversial. The coverages are reported to be either close to a single In layer (1.0-1.2 ML) or close to a double layer (2.4 ML) for both "hex" and "rect" phases in several literature reports [19][20][21][22][23][24].…”

Bilayer B54, B60, and B62 Clusters in a Universal Structural Pattern

“…Another major breakthrough in boron nanostructures was the theoretical prediction, and experimental observation of two‐dimensional (2D) boron monolayers (borophenes) deposited on Ag(111) substrate by molecular beam epitaxy (MBE) , . Extensive theoretical investiagtions on a wide range of boron nanostructures have been reported in literature, with typical examples including the most stable boron α‐sheet,, 2D boron polymorphs, cage‐ and core‐shell‐like B 80 , core‐shell‐like and quasi‐planar B 84 ,, and cage‐ and core‐shell‐like B 100–102 , . Zhao and co‐workers predicted the first bilayer neutral boron cluster D 2 h B 48 at density functional theory (DFT) level in 2014, presenting another important structural motif for medium‐sized boron clusters and 2D bilayer boron sheets .…”