RT Journal Article SR Electronic T1 Nitrogen in black phosphorus structure JF Science Advances JO Sci Adv FD American Association for the Advancement of Science SP eaba9206 DO 10.1126/sciadv.aba9206 VO 6 IS 23 A1 Ji, Cheng A1 Adeleke, Adebayo A. A1 Yang, Liuxiang A1 Wan, Biao A1 Gou, Huiyang A1 Yao, Yansun A1 Li, Bing A1 Meng, Yue A1 Smith, Jesse S. A1 Prakapenka, Vitali B. A1 Liu, Wenjun A1 Shen, Guoyin A1 Mao, Wendy L. A1 Mao, Ho-kwang YR 2020 UL http://advances.sciencemag.org/content/6/23/eaba9206.abstract AB Group V elements in crystal structure isostructural to black phosphorus with unique puckered two-dimensional layers exhibit exciting physical and chemical phenomena. However, as the first element of group V, nitrogen has never been found in the black phosphorus structure. Here, we report the synthesis of the black phosphorus–structured nitrogen at 146 GPa and 2200 K. Metastable black phosphorus–structured nitrogen was retained after quenching it to room temperature under compression and characterized in situ during decompression to 48 GPa, using synchrotron x-ray diffraction and Raman spectroscopy. We show that the original molecular nitrogen is transformed into extended single-bonded structure through gauche and trans conformations. Raman spectroscopy shows that black phosphorus–structured nitrogen is strongly anisotropic and exhibits high Raman intensities in two Ag normal modes. Synthesis of black phosphorus–structured nitrogen provides a firm base for exploring new type of high-energy-density nitrogen and a new direction of two-dimensional nitrogen.