Ab initio potential energy surfaces for both the ground (X̃ A1′) and excited (Ã A1″) electronic states of HGeCl and the absorption and emission spectra of HGeCl/DGeCl

Abstract

Potential energy surfaces for the ground (X (1)A(')) and excited (A (1)A(")) electronic states of HGeCl and the transition dipole moment surface were obtained using an internally contracted multireference configuration interaction method with the Davidson correction and an augmented correlation-consistent polarized valence quadruple zeta basis set. Calculated vibrational energy levels of HGeCl and DGeCl on both the ground and excited electronic states are in excellent agreement with available experimental data. In addition, the absorption and emission spectra of both HGeCl and DGeCl were obtained using an efficient single Lanczos propagation method and the agreement with experimental spectra is also excellent.

Ab Initio Potential Energy Surfaces for Both the Ground (X̃1A′) and Excited (ALi1, Lin2, Xie3 2012Advances in Physical ChemistrySelf Cite33040View full textAdd to dashboardCite

“…In the present work, we extend our previous studies on the HGeCl [18], HGeBr [19], and HSiCl [20] systems by reporting accurate ab initio PESs for both the ground ( X 1 A ) and excited ( A 1 A ) electronic states of HSiBr using the coupled cluster singles and doubles with perturbative triples method [CCSD(T)] and the internally contracted multireference configuration interaction method with the (0, 0, 9) (0, 0, 10) (0, 0, 11) (1, 0, 6) (2, 0, 4) (3, 0, 0)…”

“…After primary test calculations, the state-averaged complete active space self-consistent field (SA-CASSCF) [27,28] for equally weighted 1 1 A and 2 1 A states were employed with a large active space (18 active electrons in 12 active orbitals) to further consider the core-valence correlation effect [15,[18][19][20]. The remnant sixteen core orbitals were kept doubly occupied but fully optimized.…”

New ab initio potential energy surfaces for both the ground (X̃1A′) and excited (Ã1A″) electronic states of HSiCl and the absorption and emission spectra of HSiCl/DSiCl

“…After primary test calculations, we chose 1 1 A″ and 2 1 A″ states for state‐averaged calculations in the CASSCF24, 25 step. To further consider the core‐valence correlation effect,13, 16, 17, 26 we used 12 active orbitals with 18 electrons. The remnant seven core orbitals were fully optimized, while constrained to be doubly occupied.…”

“…Attention needs to be paid to the fact that the PES of $ \tilde A^1 A'' $ was calculated by CASSCF/MRCI/aug‐cc‐pV5Z using a full valence active space and that the difference between the calculated vibrational frequencies and the observed values was relatively large in the higher energy region (the maximum is 155.03 cm −1 for HSiCl and 224.79 cm −1 for DSiCl). Interestingly, we have constructed accurate electronic excited state $ \tilde A^1 A'' $ PESs for similar systems such as HGeCl16 and HGeBr16, 17 recently. The five 3d orbitals are found to be very important in ab initio calculations for the $ \tilde A^1 A'' $ PES (see Refs 16.…”

“…Interestingly, we have constructed accurate electronic excited state $ \tilde A^1 A'' $ PESs for similar systems such as HGeCl16 and HGeBr16, 17 recently. The five 3d orbitals are found to be very important in ab initio calculations for the $ \tilde A^1 A'' $ PES (see Refs 16. and17 for details).…”