Accurate Potential Energy Surface and Calculated Spectroscopic Properties for CdH2 Isotopomers
journal contributionposted on 29.10.2009, 00:00 by Peter Sebald, Rainer Oswald, Peter Botschwina, Hermann Stoll, Detlev Figgen
Ab initio calculations employing the coupled cluster method CCSD(T), in conjunction with a small-core pseudopotential for the cadmium atom, have been employed to construct a near-equilibrium potential energy function (PEF) and an electric dipole moment function (EDMF) for CdH2. The significance of the spin−orbit interaction was checked and found to be of minor importance. Making use of two pieces of experimental information for the most abundant isotopomer 114CdH2, we obtained a refined PEF, which, within variational calculations of rovibrational states and wave functions, reproduces all available experimental data (S. Yu, A. Shayesteh, and P. F. Bernath, J. Chem. Phys. 2005, 122, 194301) very well. In addition, numerous predictions are made. In particular, the ν2 band origins for 114CdH2 and 114CdD2 are predicted at 605.9 and 436.9 cm−1, respectively, and the state perturbing the e parity levels of the (0,00,1) state of 114CdH2 at J = 12−17 is identified as the (0,33,0) state. Assignments for further perturbations found in the emission spectra are given as well.