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-Fo ck, density functional, coupled-cluster, and configuration interaction meth ods using an extended basis set. The energy of the ground state of CuH+ is calculated over a range of Cu-H bond lengths. More than one solution is obt ained in the Hartree-Fock calculations. These lead to different coupled-clu ster and configuration interaction energies. In the case of density functio nal theory, however, only one unique solution is obtained. The best estimat e of the equilibrium bond length is 1.485 +/- 0.015 Angstrom. The best esti mates of the isotropic hyperfine coupling is 2400 MHz for copper and 640 MH z for hydrogen with an uncertainty of about 10%. The dipolar coupling const ant at copper is about 200 MHz while it is very small for hydrogen. (C) 200 0 John Wiley & Sons, Inc.