Low‐lying states of TaGe−/0/+ clusters from the CASPT2 and DMRG‐CASPT2 calculations

Abstract

AbstractThe low‐lying states of TaGe−/0/+ clusters have been investigated with the CASPT2 and DMRG‐CASPT2 methods. The DMRG‐CASPT2 method with an active space of 20 orbitals is expected to provide highly accurate relative energies of the electronic states. The leading configurations, bond distances, bond orders, vibrational frequencies, atomic charges, and relative energies of the electronic states are reported. The ground states of TaGe−/0/+ clusters are respectively predicted as the 3Δ, 4Φ, and 5Δ. The atomic charges of Ta in these ground states are more positive than those of the Ge atom. The electron detachment energies of the anionic and neutral clusters are estimated to be 1.62 and 6.84 eV. The Franck‐Condon factor simulations for the detachments of one electron from the anionic and neutral clusters exhibit extensively vibrational progressions because of the large structural difference between the initial and the final state.