Ab initio structure and vibration-rotation dynamics of germylene, GeH2.

Abstract

Accurate structure and potential energy surface of germylene, GeH2 , in its ground electronic state 1 A1 were determined from ab initio calculations using the coupled-cluster approach in conjunction with the correlation-consistent basis sets up to sextuple-zeta quality. The Born-Oppenheimer equilibrium structural parameters for the 1 A1 state are estimated to be re (GeH) = 1.5793 Å and ∠e (HGeH) = 91.19∘ . The term value Te for the lowest excited electronic state ã3 B1 of GeH2 is predicted to be 9140 cm-1 . The vibration-rotation energy levels for the 1 A1 state of the 74 GeH2 , 74 GeD2 , 72 GeH2 , and 70 GeH2 isotopologues were determined using a variational approach and compared with the experimental data. The role of the core-electron correlation, higher-order valence-electron correlation, scalar relativistic, spin-orbit, and adiabatic effects for prediction of the structure and vibration-rotation dynamics of the GeH2 molecule is discussed. © 2019 Wiley Periodicals, Inc.