Intense Laser Physics Theory Unit, Illinois State University, Normal, Illinois 61790, United States.
Department of Chemistry & Biochemistry, Texas Christian University, 2800 S. University Drive, Fort Worth, Texas 75039, United States.
J Phys Chem A. 2023 Apr 27;127(16):3684-3691. doi: 10.1021/acs.jpca.2c08616. Epub 2023 Apr 13.
Pancake bonding between π-conjugated radicals challenges conventional electronic structure approximations, due to the presence of both dispersion (van der Waals) interactions and "strong" electron correlation. Here we use a reimagined wave function-in-density functional theory (DFT) approach to model pancake bonds. Our generalized self-interaction correction extends DFT's reference system of noninteracting electrons, by introducing electron-electron interactions within an active space. We show that a small variation on our previous derivation recovers a DFT-corrected complete active space method proposed by Pijeau and Hohenstein. Comparison of the two approaches shows that the latter provides reasonable dissociation curves for single bonds and pancake bonds, including excited states inaccessible to conventional linear response time-dependent DFT. The results motivate broader adoption of wavefunction-in-DFT approaches for modeling pancake bonds.
π 共轭自由基之间的夹心键合挑战了传统的电子结构近似，因为存在色散（范德华）相互作用和“强”电子相关。在这里，我们使用一种重新构想的波函数-密度泛函理论（DFT）方法来模拟夹心键。我们的广义自相互作用校正通过在活性空间内引入电子-电子相互作用，扩展了 DFT 的非相互作用电子参考系。我们表明，对我们之前的推导进行微小的修改，就可以恢复 Pijeau 和 Hohenstein 提出的经过 DFT 校正的完整活性空间方法。两种方法的比较表明，后者为单键和夹心键提供了合理的离解曲线，包括传统线性响应时间相关 DFT 无法访问的激发态。这些结果促使更广泛地采用波函数-DFT 方法来模拟夹心键。
