Theoretical studies on CuF⁺, CuF, CuF^-, CuF2, and CuF2^-

Ab initio SCF studies were performed with Cu and F basis sets of near-Hartree-Fock (HF) limit quality to obtain accurate SCF results for the molecular ground state properties of CuF+, CuF, CuF-, CuF2, and CuF2-, as well as for the first two low-lying excited states of CuF2. A study on the effects of electron correlation was carried out by Møller-Plesset (MP) and configuration interaction (Cl) calculations. The effect of relativity on the63Cu nuclear quadrupole coupling in CuF was determined by use of a coupled HF procedure for a first-order spin-orbital-averaged Pauli operator. At the HF level the63Cu coupling constant was found to be 35.8 MHz (in e2qQ h-1), while allowing for relativity the value was reduced to 29.1 MHz, which is in better agreement with the experimental value of 22.0 MHz. The calculated molecular properties for CuF [re = 1.737 Å, De=4.38 eV, ωe = 562 cm-1 (MP4);re= 1.796 Å, De = 3.91 eV, ωe=585 cm-1 (CISD)] were in good agreement with experiment (re = 1.745 Å, De = 4.43 eV, ωe=623 cm-1). The adiabatic ground-state potential curve of CuF+ avoids crossing near the equilibrium distance between the two ionic potential curves Cu+-F and Cu2+-F-. At the crossing point the Cu and F electric field gradients show a sharp discontinuity. © 1990 VCH Publishers, Inc.