Electronic states and nature of bonding of the molecule PdGe by all electron ab initio HF–CI calculations and mass spectrometric equilibrium experiments

In the present work we present all-electron ab initio Hartree–Fock (HF) and configuration interaction (CI) calculations of six electronic states of the PdGe molecule. The molecule is predicted to have a 3Pi ground state and two low-lying excited states 3Sigma− and 1Sigma+. The electronic structure of the PdGe molecule has been rationalized in a simple molecular orbital picture. As part of the PdGe molecule the Pd atom essentially retains its (4d)10 ground term configuration. The chemical bond in the PdGe molecule has been interpreted in terms of donation and backdonation of charge. The bond is polar with a small charge transfer from the Pd to the Ge atom. The dissociation energy of the PdGe molecule has been determined from the mass spectrometric equilibrium data combined with the theoretical results as D⁰₀ =252.0±10.5 kJ mol−1. The Journal of Chemical Physics is copyrighted by The American Institute of Physics.