Akama Tomoko, Kobayashi Masato, Nakai Hiromi
Department of Chemistry, School of Science and Engineering, Waseda University, Tokyo 169-8555, Japan.
J Comput Chem. 2007 Sep;28(12):2003-12. doi: 10.1002/jcc.20707.
The divide-and-conquer (DC) method, which is one of the linear-scaling methods avoiding explicit diagonalization of the Fock matrix, has been applied mainly to pure density functional theory (DFT) or semiempirical molecular orbital calculations so far. The present study applies the DC method to such calculations including the Hartree-Fock (HF) exchange terms as the HF and hybrid HF/DFT. Reliability of the DC-HF and DC-hybrid HF/DFT is found to be strongly dependent on the cut-off radius, which defines the localization region in the DC formalism. This dependence on the cut-off radius is assessed from various points of view: that is, total energy, energy components, local energies, and density of states. Additionally, to accelerate the self-consistent field convergence in DC calculations, a new convergence technique is proposed.
分治（DC）方法是一种避免对福克矩阵进行显式对角化的线性标度方法，迄今为止主要应用于纯密度泛函理论（DFT）或半经验分子轨道计算。本研究将DC方法应用于包含哈特里 - 福克（HF）交换项的计算，如HF和混合HF/DFT。发现DC - HF和DC - 混合HF/DFT的可靠性强烈依赖于截止半径，该半径在DC形式体系中定义了局域化区域。从各种角度评估了对截止半径的这种依赖性：即总能量、能量分量、局域能量和态密度。此外，为了加速DC计算中的自洽场收敛，提出了一种新的收敛技术。
