Calculation of hyperfine structure constants of small molecules using Z-vector method in the relativistic coupled-cluster framework

Abstract

The Z-vector method in the relativistic coupled-cluster framework is employed to calculate the parallel and perpendicular components of the magnetic hyperfine structure constant of a few small alkaline earth hydrides (BeH, MgH, and CaH) and fluorides (MgF and CaF). We have compared our Z-vector results with the values calculated by the extended coupled-cluster (ECC) method reported in Phys. Rev. A 91 022512 (2015). All these results are compared with the available experimental values. The Z-vector results are found to be in better agreement with the experimental values than those of the ECC values. Magnetic hyperfine structure constants of some small molecules are calculated using Z-vector method in the relativistic coupled-cluster framework and the comparison with the reported extended coupled-cluster results reveals that Z-vector method can produce more accurate wavefunction in the near nuclear region than the extended coupled-cluster method.