论文标题
一项基准研究的基准研究是用广义活动空间驱动相似性重归其化组计算的有机分子的核心状态
A benchmark study of core-excited states of organic molecules computed with the generalized active space driven similarity renormalization group
论文作者
论文摘要
这项工作研究了使用多差方法计算出的X射线吸收光谱的准确性和精度，该方法将广义的活动空间（气体）参考与驱动相似性重新归一化组（DSRG）相结合。我们采用有机分子（Xaboom）集的X射线吸收基准，由116个来自有机分子的116个过渡[T. T. Fransson等人，J。Chem。理论计算。 17，1618（2021）]。检查和基准测试了全价活动空间的几个近似值。发现在扰动理论中截断为二阶的气-DSRG计算的绝对激发能和强度，可以系统地低估实验和参考理论值。三阶扰动校正显着提高了气-DSRG绝对激发能的准确性，从而使实验值的平均绝对偏差降至0.32 eV。对于二阶扰动理论，臭氧分子和乙二基酸特别具有挑战性，并详细检查以评估活动空间截断和入侵态的重要性。
This work examines the accuracy and precision of X-ray absorption spectra computed with a multireference approach that combines generalized active space (GAS) references with the driven similarity renormalization group (DSRG). We employ the X-ray absorption benchmark of organic molecules (XABOOM) set, consisting of 116 transitions from mostly organic molecules [T. Fransson et al., J. Chem. Theory Comput. 17, 1618 (2021)]. Several approximations to a full-valence active space are examined and benchmarked. Absolute excitation energies and intensities computed with the GAS-DSRG truncated to second-order in perturbation theory are found to systematically underestimate experimental and reference theoretical values. Third-order perturbative corrections significantly improve the accuracy of GAS-DSRG absolute excitation energies, bringing the mean absolute deviation from experimental values down to 0.32 eV. The ozone molecule and glyoxylic acid are particularly challenging for second-order perturbation theory and are examined in detail to assess the importance of active space truncation and intruder states.
