AI 中文总结
本文针对分子光离化理论模型的基组依赖问题，通过在高斯基组中添加弥散函数，实现了手性分子多光子电离相关可观测量的系统收敛，为该领域提供了高效可迁移的计算方法。
AI 中文摘要
对光电子离化可观测量的精确描述是分子光离化理论模型的核心挑战。在标准电子结构方法中，连续态由高斯基组展开的未占据Hartree-Fock轨道表示；由于这类基组针对束缚态优化，计算得到的可观测量可能存在显著的基组依赖性。本文中，我们在上述基组中添加弥散函数，研究随机取向手性分子多光子电离中的光电子圆二色性（PECD）、各向异性参数及前后向电离时间延迟的收敛性。所有可观测量均随添加的弥散函数数量呈系统收敛，解决了此前观测到的基组差异，表明添加弥散函数后的基组能更精确地描述中间连续态。特别地，我们的全从头算得到的前后向时间延迟与近期测量结果定性一致，而此前理论描述依赖经验模型。因此，弥散添加为分子多光子光离化的高斯基组收敛计算提供了计算高效且可迁移的途径。
英文摘要
An accurate description of photoionization observables is a central challenge for theoretical models of molecular photoionization. Within standard electronic-structure approaches, the continuum states are represented by unoccupied Hartree-Fock orbitals expanded in Gaussian basis sets. Since these basis sets are optimized for bound states, computed observables may exhibit a noticeable basis-set dependence. Here, we augment these basis sets with diffuse functions and investigate the convergence of photoelectron circular dichroism (PECD), anisotropy parameters, and the forward backward ionization time delay in the multiphoton ionization of randomly oriented chiral molecules. All observables converge systematically with the number of added diffuse functions, resolving previously observed basis-set discrepancies and indicating that the augmented basis sets provide a more accurate representation of the intermediate continuum states. In particular, our fully ab initio calculations yield forward-backward time delays in qualitative agreement with recent measurements, for which previous theoretical descriptions relied on empirical modeling. Diffuse augmentation thus provides a computationally efficient and transferable route to converged Gaussian-basis calculations for molecular multiphoton photoionization.
CommentsAPS REVTeX 4.2 format; 15 pages, 12 figures (including appendix). Preprint
