Cagelike Diamondoid Nitrogen at High Pressures

Xiaoli Wang, Yanchao Wang, Maosheng Miao, Xin Zhong, Jian Lv, Tian Cui, Jianfu Li, Li Chen, Chris J. Pickard, and Yanming Ma

Phys. Rev. Lett. 109, 175502 – Published 24 October 2012

Abstract

Under high pressure, triply bonded molecular nitrogen dissociates into singly bonded polymeric nitrogen, a potential high-energy-density material. The discovery of stable high-pressure forms of polymeric nitrogen is of great interest. We report the striking stabilization of cagelike diamondoid nitrogen at high pressures predicted by first-principles structural searches. The diamondoid structure of polymeric nitrogen has not been seen in any other elements, and it adopts a highly symmetric body-centered cubic structure with lattice sites occupied by diamondoids, each of which consists of ten nitrogen atoms, forming a $N_{10}$ tetracyclic cage. Diamondoid nitrogen possesses a wide energy gap and is energetically most stable among all known polymeric structures above 263 GPa, a pressure that is accessible to a high-pressure experiment. Our findings represent a significant step toward the understanding of the behavior of solid nitrogen at extreme conditions.

Received 19 June 2012

DOI:https://doi.org/10.1103/PhysRevLett.109.175502

Authors & Affiliations

Xiaoli Wang^1,2, Yanchao Wang³, Maosheng Miao^4,2, Xin Zhong³, Jian Lv³, Tian Cui³, Jianfu Li^1,*, Li Chen¹, Chris J. Pickard⁵, and Yanming Ma^3,2,†

¹Institute of Condensed Matter Physics, Linyi University, Linyi 276005, People’s Republic of China
²Beijing Computational Science Research Center, Beijing 100084, People’s Republic of China
³State Key Lab of Superhard Materials, Jilin University, Changchun 130012, People’s Republic of China
⁴Materials Research Lab, University of California–Santa Barbara, Santa Barbara, California 93110, USA
⁵Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom