Predictions on High-Power Trivalent Metal Pentazolate Salts

Kang Xia; Jianan Yuan; Xianxu Zheng; Cong Liu; Hao Gao; Qiang Wu; Jian Sun

doi:10.1021/acs.jpclett.9b02383

Predictions on High-Power Trivalent Metal Pentazolate Salts

J Phys Chem Lett. 2019 Oct 17;10(20):6166-6173. doi: 10.1021/acs.jpclett.9b02383. Epub 2019 Oct 1.

Authors

Kang Xia¹, Jianan Yuan¹, Xianxu Zheng², Cong Liu¹, Hao Gao¹, Qiang Wu², Jian Sun¹

Affiliations

¹ National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 210093 , China.
² National Key Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics , China Academy of Engineering Physics , Mianyang 621900 , Sichuan , China.

PMID: 31560550
DOI: 10.1021/acs.jpclett.9b02383

Abstract

High-energy-density materials (HEDMs) have been intensively studied for their significance in fundamental sciences and practical applications. Here, using the molecular crystal structure search method based on first-principles calculations, we have predicted a series of metastable energetic trivalent metal pentazolate salts MN₁₅ (M= Al, Ga, Sc, and Y). These compounds have high energy densities, with the highest nitrogen content among the studied nitrides so far. Pentazolate N₅^- molecules stack up face-to-face and form wave-like patterns in the C222₁ and Cc symmetries. The strong covalent bonding and very weak noncovalent interactions with nonbonded overlaps coexist in these ionic-like structures. We find MN₁₅ molecular structures are mechanically stable up to high temperature (∼1000 K) and ambient pressure. More importantly, these trivalent metal pentazolate salts have high detonation pressure (∼80 GPa) and velocity (∼12 km/s). Their detonation pressures exceeding that of TNT and HMX make them good candidates for high-brisance green energetic materials.