Mostafanejad Mohammad, Liebenthal Marcus Dante, DePrince A Eugene
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States.
Department of Chemistry and Biochemistry, Ithaca College, Ithaca, New York 14850, United States.
J Chem Theory Comput. 2020 Apr 14;16(4):2274-2283. doi: 10.1021/acs.jctc.9b01178. Epub 2020 Mar 9.
A global hybrid extension of multiconfiguration pair-density functional theory (MC-PDFT) is developed. Using a linear decomposition of the electron-electron repulsion term, a fraction λ of the nonlocal exchange interaction, obtained from variational two-electron reduced-density matrix (v2RDM)-driven complete active-space self-consistent field (CASSCF) theory, is combined with its local counterpart, obtained from an on-top pair-density functional. The resulting scheme (called λ-MC-PDFT) inherits the benefits of MC-PDFT (e.g., its simplicity and the resolution of the symmetry dilemma) and, when combined with the v2RDM approach to CASSCF, requires only polynomially scaling computational effort. As a result, λ-MC-PDFT can efficiently describe static and dynamical correlation effects in strongly correlated systems. The efficacy of the approach is assessed for several challenging multiconfigurational problems, including the dissociation of molecular nitrogen, the double dissociation of a water molecule, and the 1,3-dipolar cycloadditions of ozone to ethylene and ozone to acetylene in the O3ADD6 benchmark set.
发展了多组态对密度泛函理论（MC-PDFT）的一种全局混合扩展方法。利用电子-电子排斥项的线性分解，将从变分双电子约化密度矩阵（v2RDM）驱动的完全活性空间自洽场（CASSCF）理论获得的非局域交换相互作用的一部分λ，与其从顶对密度泛函获得的局域对应项相结合。由此产生的方案（称为λ-MC-PDFT）继承了MC-PDFT的优点（例如其简单性和对称性困境的解决），并且当与v2RDM方法用于CASSCF相结合时，仅需要多项式缩放的计算量。因此，λ-MC-PDFT能够有效地描述强关联系统中的静态和动态关联效应。针对几个具有挑战性的多组态问题评估了该方法的有效性，包括分子氮的解离、水分子的双解离以及在O3ADD6基准集中臭氧与乙烯和臭氧与乙炔的1,3-偶极环加成反应。
