Stability of Sulfur Nitrides: A First-Principles Study

Abstract

A systematic computational study on the structural, electronic, and bonding properties of binary sulfur nitrides has been performed using the projector augmented wave method based on density functional theory. The pressure–composition phase diagram of the S–N system has been established. The simulated pressure–temperature phase diagram and X-ray diffraction pattern of (SN) x explain the experimentally observed two-phase coexistence. The crystal structure of experimentally observed orthorhombic (SN) x is predicted. The high-pressure phase transition of (SN) x has been studied. Sulfur–sulfur interactions induced by localized sulfur 3p z electrons are found in the high-pressure phase of (SN) x . With increasing nitrogen composition, the coordination number of sulfur atoms increases from two to six in the S–N system. Furthermore, two nitrogen-rich sulfur nitrides SN2 and SN4 have been found at high pressure. SN4 exhibits a high energy density (2.66 kJ·g–1), which makes it potentially interesting for industrial applications as a high energy density material.

High-pressure formation of antimony nitrides: a first-principles study

“…However, an unusual B 3 N 5 with high hardness (∼44 GPa) and high energy density (∼3.44 kJ g −1 ) had been predicted by Li et al 25 Besides, novel high-pressure compounds in the C–N system and S–N system are also considered in the exploration of high-energy materials. 26,27 Up to now, several binary systems have been studied. And some new polynitrogen forms including tetrazadiene (N 4 ), pentazole (N 5 ), hexazine (N 6 ) and extended chains (N ∞ ) have been reported in these binary systems.…”

High Pressure Investigation of the S–N2System up to the Megabar Range: Synthesis and Characterization of the SN2Solid

“…1,19 From their investigation, it was found that in most cases Hückel molecular orbital theory and the notion of aromaticity can serve to explain the high kinetic stability of many S-N rings, namely one of the most stable, S2N2. [20][21][22][23] The maximization of the number of S-N bonds within the structure was shown to be intrinsically related to their kinetic stability. 3,24 None of the many synthesized sulfur-nitrogen compounds are however, more stable at ambient pressure than a mixture of the pure elements and thus rely solely on their kinetic stabilization-the height of their activation barrier-to prevent their spontaneous decomposition.…”

Neutral binary chalcogen–nitrogen and ternary S,N,P molecules: new structures, bonding insights and potential applications

“…In 2017 Cui and co-workers performed particle-swarm optimisation calculations on the sulfur-nitrogen system up to 200 GPa. 39 Three binary sulfur-nitrogen solids were determined to be thermodynamically stable: Pnma (SN) x , Pnnm SN 2 , and C2/c SN 4 at pressures of 37, 43 and 48 GPa, respectively. Their crystal structures are depicted in Fig.…”