Hong Feng, Lu Jian, Gao Heng, Ren Wei, Xu Run, Xu Fei, Ma Zhongquan, Yan Yanfa
Department of Physics, International Centre for Quantum and Molecular Structures, SHU-Solar E R & D Lab, Shanghai University, Shanghai 200444, People's Republic of China.
J Phys Condens Matter. 2016 Sep 14;28(36):365502. doi: 10.1088/0953-8984/28/36/365502. Epub 2016 Jul 12.
The crystal structures of Os2C were extensively investigated using the structure search method from the first-principles calculations. In contrast to the P6 3 /mmc phase previously proposed as the ground state at ambient pressure, an energetically favorable structure with space group P-6m2 was found more stable at ambient condition. The structural stabilities of the new phase are confirmed by the phonon dispersion and elastic constants. Further calculations indicate that the newly predicted P-6m2 phase is ultra-incompressible with a high bulk modulus of 387 GPa and has a larger ideal shear strength than the P6 3 /mmc phase.
