First-principles study of ground-state properties of U2Mo.
First-principles study of ground-state properties of U2Mo.
复制标题
DOI：
10.1039/c4cp03841j
复制
发表时间：
2014-11
期刊：
影响因子：
--
通讯作者：
Xin Wang;Xiyue Cheng;Yuting Zhang;Ronghan Li;Weiwei Xing;Pengcheng Zhang;Xing-Qiu Chen
中科院分区：
文献类型：
--
作者：
Xin Wang;Xiyue Cheng;Yuting Zhang;Ronghan Li;Weiwei Xing;Pengcheng Zhang;Xing-Qiu Chen
通过第一性原理计算，我们系统地研究了金属间化合物U_2Mo基态相的结构、弹性、振动、热和电子性质.我们的研究结果表明，先前合成的I4/mmm结构的U2 Mo是一个亚稳相和不稳定的，既不结晶也不振动在基态。结合进化结构搜索，我们的第一性原理计算提出了一个新的基态Pmmn相，这在理论上已被证实是稳定的，无论是振动和振动。此外，通过DFT + D方法讨论了货车德瓦耳斯相互作用对U、Mo固体和U_2Mo合金的结构、弹性和振动性质的影响，发现在纯U、Mo固体和U_2Mo合金中，van der Waals相互作用的影响很弱。电子能带结构的分析表明，在费米能级处态密度出现了一个深谷，证明了其电子稳定性。此外，我们还进一步研究了我们提出的Pmmn基态相的温度依赖性结构，热膨胀和弹性性质。这些结果有望激发U2 Mo基态相的进一步实验研究。
By means of first-principles calculations, we have systematically investigated the structural, elastic, vibrational, thermal and electronic properties of the ground-state phase for the intermetallic compound U2Mo. Our results reveal that the previously synthesized I4/mmm structure of U2Mo is a metastable phase and unstable, neither thermodynamically nor vibrationally at the ground state. In combination with the evolutionary structural searches, our first-principles calculations suggest a new ground-state Pmmn phase, which has been confirmed theoretically to be stable, both thermodynamically and vibrationally. Moreover, through the DFT + D technique we have discussed the influence of van der Waals interactions on the structural, elastic and vibrational properties, revealing a weak effect in pure U and Mo solids and U2Mo alloy. The analysis of the electronic band structures evidences its electronic stabilities with the appearance of a deep valley in the density of states at the Fermi level. Moreover, we have investigated further the temperature-dependent structural, thermal expansion and elastic properties of our proposed Pmmn ground-state phase. These results are expected to stimulate further experimental investigations of the ground-state phase of U2Mo.