Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA.
Sci Rep. 2017 Jul 12;7(1):5179. doi: 10.1038/s41598-017-05402-0.
We introduce a simple criterion to identify two-dimensional (2D) materials based on the comparison between experimental lattice constants and lattice constants mainly obtained from Materials-Project (MP) density functional theory (DFT) calculation repository. Specifically, if the relative difference between the two lattice constants for a specific material is greater than or equal to 5%, we predict them to be good candidates for 2D materials. We have predicted at least 1356 such 2D materials. For all the systems satisfying our criterion, we manually create single layer systems and calculate their energetics, structural, electronic, and elastic properties for both the bulk and the single layer cases. Currently the database consists of 1012 bulk and 430 single layer materials, of which 371 systems are common to bulk and single layer. The rest of calculations are underway. To validate our criterion, we calculated the exfoliation energy of the suggested layered materials, and we found that in 88.9% of the cases the currently accepted criterion for exfoliation was satisfied. Also, using molybdenum telluride as a test case, we performed X-ray diffraction and Raman scattering experiments to benchmark our calculations and understand their applicability and limitations. The data is publicly available at the website http://www.ctcms.nist.gov/~knc6/JVASP.html.
我们提出了一个简单的标准，通过比较实验晶格常数和主要从 Materials-Project（MP）密度泛函理论（DFT）计算存储库中获得的晶格常数来识别二维（2D）材料。具体来说，如果特定材料的两个晶格常数之间的相对差异大于或等于 5%，我们预测它们是 2D 材料的良好候选者。我们已经预测了至少 1356 种这样的 2D 材料。对于所有满足我们标准的系统，我们手动创建单层系统，并计算它们的体相和单层情况下的能量、结构、电子和弹性性质。目前，该数据库包含 1012 个体相和 430 个单层材料，其中 371 个系统同时存在于体相和单层中。其余的计算正在进行中。为了验证我们的标准，我们计算了所建议的层状材料的剥离能，我们发现 88.9%的情况下满足当前公认的剥离标准。此外，我们使用二硫化钼作为测试案例，进行了 X 射线衍射和拉曼散射实验，以基准我们的计算并了解它们的适用性和局限性。该数据可在网站 http://www.ctcms.nist.gov/~knc6/JVASP.html 上公开获取。
