Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovsky Square 2, 162 00 Prague, Czech Republic.
Int J Mol Sci. 2024 Oct 6;25(19):10762. doi: 10.3390/ijms251910762.
Knowledge of reliable geometries and associated intermolecular interaction energy (Δ) values at key fragments of the potential energy surface (PES) in the gas phase is indispensable for the modeling of various properties of the pyrene dimer (PYD) and other important aggregate systems of a comparatively large size (ca. 50 atoms). The performance of the domain-based local pair natural orbital (DLPNO) variant of the coupled-cluster theory with singles, doubles and perturbative triples in the complete basis set limit [CCSD(T)/CBS] method for highly accurate predictions of the Δ at a variety of regions of the PES was established for a representative set of pi-stacked dimers, which also includes the PYD. For geometries with the distance between stacked monomers close to a value of such a distance in the Δ minimum structure, an excellent agreement between the canonical CCSD(T)/CBS results and their DLPNO counterparts was found. This finding enabled us to accurately characterize the lowest-lying configurations of the PYD, and the physical origin of their stabilization was thoroughly analyzed. The proposed DLPNO-CCSD(T)/CBS procedure should be applied with the aim of safely locating a global minimum of the PES and firmly establishing the pertaining Δ of even larger dimers in studies of packing motifs of organic electronic devices and other novel materials.
对于各种性质的苝二聚体（PYD）和其他重要的大规模聚集体系（约 50 个原子）的建模来说，了解气相中潜在能量表面（PES）关键片段的可靠几何形状和相关的分子间相互作用能（Δ）值是必不可少的。对于各种 PES 区域的Δ进行高精度预测，域基局部对自然轨道（DLPNO）耦合簇理论变体与单、双和微扰三的完全基组限制[CCSD（T）/CBS]方法的性能已经建立，该方法对于一组代表性的π堆积二聚体是有效的，其中还包括 PYD。对于堆叠单体之间的距离接近Δ最小结构中该距离的值的几何形状，发现规范 CCSD（T）/CBS 结果与其 DLPNO 对应物之间存在极好的一致性。这一发现使我们能够准确地描述 PYD 的最低能级构型，并彻底分析了它们稳定化的物理起源。所提出的 DLPNO-CCSD（T）/CBS 程序应应用于安全定位 PES 的全局最小值，并在有机电子器件和其他新型材料的包装图案研究中确定甚至更大二聚体的相关Δ。
