Theoretical investigation of electronic structure and ESR hyperfine parameters for the CuH+ molecule

The electronic structure of CuH+ is investigated with the aid of Hartree–Fock, density functional, coupled-cluster, and configurationinteraction methods using an extended basis set. The energy of the ground state ofCuH+ is calculated over a range of CuH bond lengths. More than one solution is obtained in the Hartree–Fock calculations. These lead to different coupled-cluster and configuration interaction energies. In the case of density functional theory, however, only one unique solution is obtained. The best estimate of the equilibrium bond length is 1.485±0.015 Å. The best estimates of the isotropic hyperfine coupling is 2400 MHz for copper and 640 MHz for hydrogen with an uncertainty of about 10%. The dipolar coupling constant at copper is about 200 MHz while it is very small for hydrogen.