Novel Rubidium Poly-Nitrogen Materials at High Pressure
Abstract
First-principles crystal structure search is performed to predict novel rubidium poly-nitrogen materials at high pressure by varying the stoichiometry, i. e. relative quantities of the constituent rubidium and nitrogen atoms. Three compounds of high nitrogen content, RbN5, RbN2, and Rb4N6, are discovered. Rubidium pentazolate (RbN5) becomes thermodynamically stable at pressures above [30]GPa. The charge transfer from Rb to N atoms enables aromaticity in cyclo-N_5- while increasing the ionic bonding in the crystal. Rubidium pentazolate can be synthesized by compressing rubidium azide (RbN3) and nitrogen (N2) precursors above [9.42]GPa, and its experimental discovery is aided by calculating the Raman spectrum and identifying the features attributed to N_5- modes. The two other interesting compounds, RbN2 containing infinitely-long single-bonded nitrogen chains, and Rb4N6 consisting of single-bonded N6 hexazine rings, become thermodynamically stable at pressures exceeding [60]GPa. In addition to the compounds with high nitrogen content, Rb3N3, a new compound with 1:1 RbN stoichiometry containing bent N3 azides is found to exist at high pressures.
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.