Abstract Using particle swarm optimization algorithm, we predicted two new atmospheric phases and two new high pressure phasess for OsB2 in the pressure range from 0 to 100 GPa. By first-principles calculations with density functional theory, we further investigate the structure, phase stability, elastic properties, hardness, electronic properties for these structures. Results show that they are all thermodynamically and mechanically stable. The calculations of the enthalpy-pressure relationship was calculated to discuss the possible phase transition of OsB2 at high pressure condition. The bulk modulus, shear modulus, Young’s modulus and Poisson’s ratio were computed to discuss their elastic properties. The calculations of hardness show that they are all hard materials. Especially for atmospheric I4/mmm phase and high pressure Fddd phase, their hardness are larger than 32 GPa, not far from the hardness of superhard materals. Density of states and charge density of various OsB2 phases were presented to explore the reason for their high hardness.

中文翻译：

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从第一性原理计算预测的二硼化锇的结构、弹性、电子和硬度特性

摘要 使用粒子群优化算法，我们预测了 OsB2 在 0 到 100 GPa 压力范围内的两个新的大气相和两个新的高压相。通过密度泛函理论的第一性原理计算，我们进一步研究了这些结构的结构、相稳定性、弹性特性、硬度、电子特性。结果表明它们在热力学和机械上都是稳定的。计算焓-压关系是为了讨论OsB2 在高压条件下可能发生的相变。计算体积模量、剪切模量、杨氏模量和泊松比以讨论它们的弹性特性。硬度计算表明，它们都是硬质材料。特别是对于常压 I4/mmm 相和高压 Fddd 相，它们的硬度大于32 GPa，与超硬材料的硬度相差不远。介绍了各种 OsB2 相的态密度和电荷密度，以探讨其高硬度的原因。