Benchmarking of the Fock-space coupled-cluster method and uncertainty estimation: Magnetic hyperfine interaction in the excited state of BaF
Malika Denis, Pi A. B. Haase, Maarten C. Mooij, Yuly Chamorro, Parul Aggarwal, Hendrick L. Bethlem, A. Boeschoten, Anastasia Borschevsky, Kevin Esajas, Yongliang Hao, Steven Hoekstra, Joost W. F. van Hofslot, Virginia R. Marshall, T. B. Meijknecht, R. G. E. Timmermans, Anno Touwen, W. Ubachs, Lorenz Willmann, Yanning Yin
Abstract
We present an investigation of the performance of the relativistic multireference Fock-space coupled-cluster (FSCC) method for predicting molecular hyperfine structure (HFS) constants, including a thorough computational study to estimate the associated uncertainties. In particular, we considered the $^{19}\mathrm{F}$ HFS constant in the ground and excited states of BaF. The ab initio values were compared to the recent experimental results, and good overall agreement within the theoretical uncertainties was found. This work demonstrates the predictive power of the FSCC method and the reliability of the established uncertainty estimates, which can be crucial in cases where the calculated property cannot be directly compared to experiment.