Atom-projected and angular momentum resolved density of states in the ONETEP code
Atom-projected and angular momentum resolved density of states in the ONETEP code
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DOI：
10.1088/2516-1075/ab34f5
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发表时间：
2019-09-01
影响因子：
2.6
通讯作者：
Skylaris, C-K
中科院分区：
文献类型：
--
作者：
Aarons, J.;Verga, L. G.;Skylaris, C-K
局域动量和角动量投影态密度(DOS)是从密度泛函理论计算中获得的宝贵信息来源。在这项工作中，我们在ONETEP的线性标度密度泛函理论中描述了一个理论框架，它允许计算局域(原子投影)和角动量投射态密度L-p-DOS。我们描述了四种可用于以角动量分辨率投影DOS的不同基础，并进行了一系列测试来比较它们。我们用ONETEP的L-p-DOS程序对平面波DFT程序CASTEP的结果进行了验证。当我们使用准原子轨道作为投影基组时，观察到了ONETEP和CASTEP的电荷溢出参数之间的相似结果。一般来说，对于使用非收缩球面波作为角动量分解基础的投影，电荷溢出参数显示出非常低的值。我们还计算了尺寸不断增大的立方八面体铂纳米粒子(111)面上铂原子的d带和d带中心，这是L-p-DOS在多相催化中常用的电子描述符的一个例子。有趣的是，不同的投影基础导致了相似的结论，显示了用于此类研究的实施方法的可靠性。这些方法在ONETEP等线性尺度框架中的实施为分析复杂纳米结构材料的电子结构提供了另一种工具。
Local and angular momentum projected densities of states (DOS) are invaluable sources of information that can be obtained from density functional theory calculations. In this work, we describe a theoretical framework within ONETEP's linear-scaling DFT formalism that allows the calculation of local (atom-projected) and angular momentum projected density of states l-p-DOS. We describe four different bases that can be used for projecting the DOS with angular momentum resolution and perform a set of tests to compare them. We validate the results obtained with ONETEP's l-p-DOS against the plane-wave DFT code CASTEP. Comparable results between ONETEP's and CASTEP's charge spilling parameters are observed when we use pseudo-atomic orbitals as the projection basis sets. In general, the charge spilling parameters show remarkably low values for projections using non-contracted spherical waves as the angular momentum resolved basis. We also calculate the d-band and d-band centres for Pt atoms in (1 1 1) facets of cuboctahedral Pt nanoparticles of increasing size, which is an example of l-p-DOS application commonly used as an electronic descriptor in heterogeneous catalysis. Interestingly, the different projection bases lead to similar conclusions, showing the reliability of the implemented method for such studies. The implementation of these methods in a linear-scaling framework such as ONETEP provides another tool for analysing the electronic structure of complex nanostructured materials.