Manby Frederick R, Stella Martina, Goodpaster Jason D, Miller Thomas F
J Chem Theory Comput. 2012 Aug 14;8(8):2564-2568. doi: 10.1021/ct300544e. Epub 2012 Jul 17.
Density functional theory (DFT) provides a formally exact framework for quantum embedding. The appearance of nonadditive kinetic energy contributions in this context poses significant challenges, but using optimized effective potential (OEP) methods, various groups have devised DFT-in-DFT methods that are equivalent to Kohn-Sham (KS) theory on the whole system. This being the case, we note that a very considerable simplification arises from doing KS theory instead. We then describe embedding schemes that enforce Pauli exclusion via a projection technique, completely avoiding numerically demanding OEP calculations. Illustrative applications are presented using DFT-in-DFT, wave-function-in-DFT, and wave-function-in-Hartree-Fock embedding, and using an embedded many-body expansion.
密度泛函理论（DFT）为量子嵌入提供了一个形式上精确的框架。在此背景下，非加和动能贡献的出现带来了重大挑战，但通过使用优化有效势（OEP）方法，多个研究团队设计出了全系统等效于科恩-沈（KS）理论的DFT中的DFT方法。既然如此，我们注意到改用KS理论会带来非常可观的简化。然后，我们描述了通过投影技术强制执行泡利不相容原理的嵌入方案，完全避免了数值要求高的OEP计算。使用DFT中的DFT、波函数中的DFT和波函数中的哈特里-福克嵌入，并使用嵌入多体展开，给出了示例应用。
