Computational discovery of a new rhombohedral diamond phase

Abstract

We identify by first-principles calculations a new diamond phase in R3c (D 6 3d) symmetry, which has a 16-atom rhombohedral primitive cell, thus termed R16 carbon. This rhombohedral diamond comprises a characteristic all-sp 3 six-membered-ring bonding network, and it is energetically more stable than previously identified diamondlike six-membered-ring bonded BC8 and BC12 carbon phases. A phonon mode analysis verifies the dynamic structural stability of R16 carbon, and electronic band calculations reveal that it is an insulator with a direct band gap of 4.45 eV. Simulated x-ray diffraction patterns provide an excellent match to recently reported distinct diffraction peaks found in milled fullerene soot, suggesting a viable experimental synthesis route. These findings pave the way for further exploration of this new diamond phase and its outstanding properties.

Three-dimensional graphene networks modified with acetylenic linkages for high-performance optoelectronics and Li-ion battery anode material

“…S3a, c) confirm the band edges of conduction/valence bands are mainly contributed from p orbitals. To our surprise, the calculated optical absorption is much stronger than that of ZnO, GaN, CKL, the recently realized direct-gap semiconductor -T-Carbon, direct-gap semiconducting R16/h-Carbon [43,46], and diamond (see Fig. 3b).…”

Theoretical design of all-carbon networks with intrinsic magnetism

“…This is achieved by stacking the graphene layers and connecting the layers with acetylenic linkages (−C ≡ C −). The essential point is that for each layer, the acetylenic linkages [26,27], carboneyane [28], graphyne [29,30], diamond [31][32][33], graphite [33], and graphene [34], are also To evaluate the stability of these 2D and 3D carbon structures, we have calculated their phonon spectra. As shown in Fig.…”

“…graphyne [29,30], diamond [31][32][33], graphite [33], and graphene [34], are also To evaluate the stability of these 2D and 3D carbon structures, we have calculated their phonon spectra. As shown in Fig.…”

Topological nodal line semimetal in an all-sp 2 monoclinic carbon

“…We have systematically discovered the bcm-C 16 carbon structure with a structural search process based on a Monte Carlo algorithm as reported for R16 [42], O16 [43], and BC14 carbon [44]. Highly efficient Tersoff potential [45] and more accurate first-principles calculations were used to screened and refined the energetics which resulted in the identification of bcm-C 16 carbon.…”