Ab initio study of ultra-incompressible ternary BeCN2 polymorph

作者：Yan, Haiyan; Wei, Qun^*; Chang, Shaomei; Guo, Ping

来源：Journal of Physics and Chemistry of Solids, 2011, 72(6): 667-672.

DOI：10.1016/j.jpcs.2011.02.013

• Crystal structure
• Elastic properties
• Thermodynamic properties
• Electronic structure

The structural, mechanical, thermodynamic, and electronic properties calculated by projector-augmented wave method are presented for BeCN2 in chalcopyrite and wurtzite-like structures. The calculated high bulk modulus (321 and 309 GPa) and large shear modulus (302 and 298 GPa) suggest that they are ultra-incompressible and hard materials. The ultra-incompressibility is attributed to a stacking of strongly three-dimensional covalent bonded CN4 and BeN4 tetrahedrons connected by corners. Thermodynamic study demonstrates that these two structures can be synthesized at ambient condition. Furthermore, the structural transformation from the wurtzite-like to the chalcopyrite phase was predicted at about 17 GPa according to the enthalpy difference calculations.

• 出版日期2011-6
• 单位西安电子科技大学; 宝鸡文理学院; 西北大学