Gardner Mason B, Westbrook Brent R, Fortenberry Ryan C, Lee Timothy J
Department of Chemistry & Biochemistry, University of Mississippi, University, MS 38677-1848, United States.
Department of Chemistry & Biochemistry, University of Mississippi, University, MS 38677-1848, United States.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Mar 5;248:119184. doi: 10.1016/j.saa.2020.119184. Epub 2020 Nov 17.
The CcCR quartic force field (QFF) methodology is capable of computing B and C rotational constants to within 35 MHz (0.14%) of experiment for triatomic and larger molecules with at least two heavy atoms. Additionally, the same constants for molecules with four or more atoms agree to within 20 MHz (0.12%) of experiment for the current test set. This work also supports previous claims that the same QFF methodology can produce fundamental vibrational frequencies with a deviation less than 5.7 cm from experiment. Consequently, this approach of augmenting complete basis set extrapolated energies with treatments of core electron correlation and scalar relativity produces some of the most accurate rovibrational spectroscopic data available.
CcCR四次力场（QFF）方法能够计算三原子及更大分子（至少有两个重原子）的B和C转动常数，计算结果与实验值的偏差在35 MHz（0.14%）以内。此外，对于当前测试集中含有四个或更多原子的分子，相同常数与实验值的偏差在20 MHz（0.12%）以内。这项工作还支持了之前的说法，即相同的QFF方法能够产生与实验偏差小于5.7 cm⁻¹的基本振动频率。因此，这种通过处理核心电子相关和标量相对论来增强完全基组外推能量的方法，能够产生一些最精确的转动振动光谱数据。
