Yim Wai-Leung, Klüner Thorsten
Institut für Reine und Angewandte Chemie, Theoretische Chemie, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, 26129 Oldenburg, Germany.
J Comput Chem. 2008 Jun;29(8):1306-15. doi: 10.1002/jcc.20889.
We used a successive charge interpolation scheme and Ridders method for differentiation, to acquire accurate charge densities and their higher derivatives in electronic structure calculations. This enables us to search bond critical points using arbitrary charge density grids. We applied the planewave-DFT code, VASP, to generate the charge density of selected benchmark molecules. The properties of bond critical points are in good agreement with those obtained by complementary implementations. We validated our GRID implementation by performing electronic structure calculations using the Gaussian 03 program package and various tools for analysis of the charge density provided by the AIMPAC package. In particular, we carefully investigate the influence of effective core potentials on the location of bond critical points, especially for a short chemical bond, which is crucial in the present pseudopotential-based planewave DFT calculations. We expect our generic implementation will not only be useful for the analysis of chemical bonding in molecules, but will particularly provide a microscopic understanding of extended systems including periodic boundary conditions.
我们在电子结构计算中使用了连续电荷插值方案和用于求导的里德斯方法，以获取精确的电荷密度及其高阶导数。这使我们能够使用任意电荷密度网格搜索键临界点。我们应用平面波密度泛函理论代码VASP来生成选定基准分子的电荷密度。键临界点的性质与通过互补实现获得的性质高度吻合。我们通过使用高斯03程序包进行电子结构计算以及使用AIMPAC包提供的各种电荷密度分析工具，验证了我们的GRID实现。特别是，我们仔细研究了有效核势对键临界点位置的影响，尤其是对于短化学键，这在当前基于赝势的平面波密度泛函理论计算中至关重要。我们期望我们的通用实现不仅对分子中的化学键分析有用，而且将特别有助于对包括周期性边界条件在内的扩展系统进行微观理解。
