Department of Chemistry, Rice University, Houston, Texas 77005, USA.
J Chem Phys. 2010 Jan 14;132(2):024111. doi: 10.1063/1.3292640.
The recently proposed constrained-pairing mean-field theory (CPMFT) is here extended to include exchange and correlation effects from density functional theory (DFT) via alternative densities. We transform from alpha and beta spin densities to alternatives based on the total and on-top pair densities. This transformation is needed because CPMFT produces correct spin-symmetry and space-symmetry adapted densities that traditional DFT functionals are not designed to work with. The inclusion of DFT exchange and correlation effects in CPMFT is well founded both on practical and methodological reasons. We present multiple benchmarks showing that in many cases our model accurately reproduces unrestricted hybrid functional energies (both regular and range separated) and does so on the correct space-symmetry and spin-symmetry surface. Our approach affords efficient inclusion of dynamical correlation effects absent in CPMFT.
最近提出的受限配对平均场理论（CPMFT）通过替代密度扩展到包括来自密度泛函理论（DFT）的交换和相关效应。我们从α和β自旋密度转换为基于总对密度和顶对密度的替代密度。由于 CPMFT 产生正确的自旋对称性和空间对称性自适应密度，而传统的 DFT 泛函并不适合使用，因此需要进行这种转换。由于实际和方法上的原因，在 CPMFT 中包含 DFT 交换和相关效应是有充分根据的。我们提出了多个基准测试，表明在许多情况下，我们的模型准确地再现了无限制的混合泛函能量（包括常规和范围分离），并且在正确的空间对称性和自旋对称性表面上进行了再现。我们的方法有效地纳入了 CPMFT 中不存在的动态相关效应。
