有效密度拟合的显式相关色散和交换色散能
Efficient density-fitted explicitly correlated dispersion and exchange dispersion energies
摘要：
自适应微扰理论（SAPT）中的首阶色散项和交换色散项$E^{(20)}_{\rm disp}$和$E^{(20)}_{\rm exch-disp}$收敛到完全基组极限的速度很慢。为了缓解这个问题，最近已经提出了这些校正的明确相关的变体$E^{(20)}_{\rm disp}$和$E^{(20)}_{\rm exch-disp}$ -F12.然而，原始的形式主义（M。Kodrycka等人，J.化学理论计算2019，15，5965-5986），虽然在提高收敛性方面非常成功，但由于需要操纵几种双电子积分，因此在计算效率方面与传统的基于轨道的SAPT相比没有竞争力。在这项工作中，我们消除了这种需要分解所有类型的两个电子积分使用强大的密度拟合。我们表明，密度拟合近似的误差是可以忽略不计的标准辅助基地，如aug-cc-pVXZ/MP2 FIT。新的实施方式允许我们研究A24数据库中的所有复合物，其基组高达aug-cc-pV 5 Z，并且$E^{(20)}_{\rm disp}$和$E^{(20)}_{\rm exch-disp}$ -F12值与其常规对应物相比表现出极大的改进基组收敛性。在计算任意能级（SAP 0，SAP 2 +3，.）的总SAPT相互作用能时，收敛良好的$E^{(20)}_{\rm disp}$-F12和$E^{(20)}_{\rm exch-disp}$ -F12数可以代替常规的$E^{(20)}_{\rm disp}$和$E^{(20)}_{\rm exch-disp}$数.我们发现，F12项的加入并不能提高低水平SAPT治疗的准确性。然而，当理论误差在高级SAPT方法如SAPT 2 +3（CCD）$δ$ MP2中被最小化时，由于F12处理，基组不完整性误差的减少大大提高了小基计算的精度。
英文摘要：
The leading-order dispersion and exchange-dispersion terms in symmetry-adapted perturbation theory (SAPT), $E^{(20)}_{\rm disp}$ and $E^{(20)}_{\rm exch-disp}$, suffer from slow convergence to the complete basis set limit. To alleviate this problem, explicitly correlated variants of these corrections, $E^{(20)}_{\rm disp}$-F12 and $E^{(20)}_{\rm exch-disp}$-F12, have been proposed recently. However, the original formalism (M. Kodrycka et al., J. Chem. Theory Comput. 2019, 15, 5965-5986), while highly successful in terms of improving convergence, was not competitive to conventional orbital-based SAPT in terms of computational efficiency due to the need to manipulate several kinds of two-electron integrals. In this work, we eliminate this need by decomposing all types of two-electron integrals using robust density fitting. We demonstrate that the error of the density fitting approximation is negligible when standard auxiliary bases such as aug-cc-pVXZ/MP2FIT are employed. The new implementation allowed us to study all complexes in the A24 database in basis sets up to aug-cc-pV5Z, and the $E^{(20)}_{\rm disp}$-F12 and $E^{(20)}_{\rm exch-disp}$-F12 values exhibit vastly improvement basis set convergence over their conventional counterparts. The well-converged $E^{(20)}_{\rm disp}$-F12 and $E^{(20)}_{\rm exch-disp}$-F12 numbers can be substituted for conventional $E^{(20)}_{\rm disp}$ and $E^{(20)}_{\rm exch-disp}$ ones in a calculation of the total SAPT interaction energy at any level (SAPT0, SAPT2+3, ...). We show that the addition of F12 terms does not improve the accuracy of low-level SAPT treatments. However, when the theory errors are minimized in high-level SAPT approaches such as SAPT2+3(CCD)$δ$MP2, the reduction of basis set incompleteness errors thanks to the F12 treatment substantially improves the accuracy of small-basis calculations.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
