Potential-energy surfaces for Pt2+H and Pt+H interactions

Publisher Website
Google Scholar
Abstract
Potential‐energy surfaces for ten electronic states of Pt2H as a function of Pt2–H distance are constructed using the complete active space multiconfiguration self‐consistent field followed by multireference singles plus doubles configuration interactions which included up to 407 000 configurations. In addition, the spin‐orbit effects were included through the relativistic configuration‐interaction method. The potential‐energy curves of low‐lying electronic states of PtH and spectroscopic constants of 11 states of PtH are also computed using the same method. The experimental A’–X2 spectroscopic bands of PtH are reassigned to the 2Σ+(II)–1/2(I) transition. A tentative reassignment of the observed B’–X1 system is also suggested. The ground state of Pt2H is found to be of E(I) symmetry when spin‐orbit effects are incorporated with a bridged structure [Re(Pt–Pt)=2.46 Å, Re(Pt–H)=1.684 Å]. A very low‐lying excited state E(II) (Te=0.14 eV) was found for Pt2H. The De(Pt2H)=59 kcal/mol compared to the De(PtH)=72 kcal/mol, indicating lower stability of the Pt2H bridge compared to PtH diatomic. Some of the low‐lying electronic states of PtH, especially 3/2 states, exhibit avoided crossings.