Ab initio investigations of the electronic structure and chemical bonding of Li{sub 2}ZrN{sub 2}

• Published in: Journal of solid state chemistry Vol. 190
• Main Authors: Matar, S.F., Poettgen, R., Al Alam, A.F., Ouaini, N.
• Format: Journal Article
• Language: English
• Published: United States 15-06-2012
• Subjects: CHEMICAL BONDS; CRYSTALS; ELECTRONIC STRUCTURE; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; LAYERS; LITHIUM NITRIDES; MATERIALS SCIENCE; PAIRING INTERACTIONS; ZIRCONIUM NITRIDES
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/J.JSSC.2012.02.038

The electronic structure of the ternary nitride Li{sub 2}ZrN{sub 2} is examined from ab initio with DFT computations for an assessment of the properties of chemical bonding. The compound is found insulating with 1.8 eV band gap; it becomes metallic and less ionic upon removal of one equivalent of Li. The chemical interaction is found mainly between Zr and N on one hand and Li and N on the other hand. While all pair interactions are bonding, antibonding N-N interactions are found dominant at the top of the valence band of Li{sub 2}ZrN{sub 2} and they become less intense upon removal of Li. From energy differences the partial delithiation leading to Li{sub 2-x}ZrN{sub 2} (x={approx}1) is favored. - Graphical abstract: Trigonal structure of Li{sub 2}ZrN{sub 2} showing the Zr-N-Li layers along the c-axis. Highlights: Black-Right-Pointing-Pointer Li{sub 2}ZrN{sub 2} calculated insulating with a 1.8 eV gap in agreement with its light green color. Black-Right-Pointing-Pointer Lithium de-intercalation is energetically favored for one out of two Li equivalents. Black-Right-Pointing-Pointer Li plays little role in the change of the structure, ensured by Zr and N binding. Black-Right-Pointing-Pointer Similar changes in the electronic structure as for various intercalated phases of ZrN.