Fishman Vladimir, Semidalas Emmanouil, Martin Jan M L
Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, 7610001 Reḥovot, Israel.
On sabbatical at Quantum Theory Project, University of Florida, Gainesville, Florida 32611, United States.
J Phys Chem A. 2024 Sep 5;128(35):7462-7470. doi: 10.1021/acs.jpca.4c03012. Epub 2024 Aug 21.
Basis set extrapolations are typically rationalized either from analytical arguments involving the partial-wave or principal expansions of the correlation energy in helium-like systems or from fitting extrapolation parameters to reference energetics for a small(ish) training set. Seeking to avoid both, we explore a third alternative: extracting extrapolation parameters from the requirement that the BSSE (basis set superposition error) should vanish at the complete basis set limit. We find this to be a viable approach provided that the underlying basis sets are not too small and reasonably well balanced. For basis sets not augmented by diffuse functions, BSSE minimization and energy fitting yield quite similar parameters.
基组外推通常要么通过涉及类氦系统中相关能的分波或主展开的解析论证来合理化，要么通过将外推参数拟合到一个小（ish）训练集的参考能量来合理化。为了避免这两种方法，我们探索了第三种方法：从基组叠加误差（BSSE）在完全基组极限下应消失的要求中提取外推参数。我们发现，只要基础基组不太小且平衡合理，这就是一种可行的方法。对于未通过弥散函数增强的基组，BSSE最小化和能量拟合产生的参数非常相似。
