期刊
JOURNAL OF PHYSICAL CHEMISTRY C
卷 117, 期 15, 页码 7885-7894出版社
AMER CHEMICAL SOC
DOI: 10.1021/jp312759j
关键词
-
资金
- U.S. Department of Energy by Lawrence Livermore National Laboratory [DE-AC52-07NA27344]
- Laboratory Directed Research and Development [12-ERD-052]
We report here on development of a density functional tight binding (DFTB) simulation approach for carbon under extreme pressures and temperatures that includes an expanded basis set and an environmentally dependent repulsive energy. We find that including d-orbital interactions in the DFTB Hamiltonian improves determination of the electronic states at high pressure temperature conditions, compared to standard DFTB implementations that utilize s- and p-orbitals only for carbon. We then determine a three-body repulsive energy through fitting to diamond, BC8, and simple cubic cold compression curve data, as well pressures from metallic liquid configurations from density functional theory (DFT) simulations Our new model (DFTB-p3b) yields approximately 2 orders of magnitude increase in computational efficiency over standard DFT while retaining its accuracy for condensed phases of carbon under a wide range of conditions, including the metallic liquid phase at conditions up to 2000 GPa and 30 000 K. Our results provide a straightforward method by which DFTB can be extended to studies of covalently bonded materials under extremely high pressures and temperatures such as the interiors of planets and other large celestial bodies.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据