Pressure-induced planar N6 rings in potassium azide

Jie Zhang; Zhi Zeng; Hai-Qing Lin; Yan-Ling Li

doi:10.1038/srep04358

Pressure-induced planar N6 rings in potassium azide

Sci Rep. 2014 Mar 12:4:4358. doi: 10.1038/srep04358.

Authors

Jie Zhang¹, Zhi Zeng², Hai-Qing Lin³, Yan-Ling Li⁴

Affiliations

¹ Key Laboratory of Materials Physics, Institute of Solid State Physics, CAS, and Department of Physics, University of Science and Technology of China, Hefei 230031, China.
² 1] Key Laboratory of Materials Physics, Institute of Solid State Physics, CAS, and Department of Physics, University of Science and Technology of China, Hefei 230031, China [2] Beijing Computational Science Research Center, Beijing 100084, China [3] Kavli Institute for Theoretical Physics China, CAS, Beijing 100190, China.
³ Beijing Computational Science Research Center, Beijing 100084, China.
⁴ School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, China.

Abstract

The first-principles method and the evolutionary algorithm are used to identify stable high pressure phases of potassium azide (KN3). It has been verified that the stable phase with space group I4/mcm below 22 GPa, which is consistent with the experimental result, will transform into the C2/m phase with pressure increasing. These two phases are insulator with N(-)(3) anions. A metallic phase with P6/mmm symmetry is preferred above 40 GPa, and the N atoms in this structure form six-membered rings which are important for understanding the pressure effect on N(-)(3) anions and phase transitions of KN3. Above the studied pressure (100 GPa), a polymerization of N6 rings may be obtained as the result of the increasing compactness.

Publication types

Research Support, Non-U.S. Gov't