Vertical Excitation Energies and Ionization Potentials of H₂S. A Size-Consistent Self-Consistent Singles and Doubles Configuration Interaction (SC)²-MR-SDCI Calculation

Abstract

The size-consistent self-consistent singles and doubles configuration interaction method using both multireference (MR) and complete active space (CAS) as SDCI generator spaces has been used to calculate both vertical excitation energies and vertical ionization potentials for the H 2 S molecule. A basis set of ANO functions, [4s3p2d1f] for S and [2s1p] for H, has been augmented with an adapted set of 4s4p4d2f Rydberg functions that have been built explicitly for this study. Several open questions concerning the vertical spectrum of the H 2 S are discussed. Rydberg states of f character have been calculated for the first time. Transitions to the outer-valence 2 B 1 (2b 1 -1 ), 2 B 2 (2b 2 -1), and 2 A 1 (5a 1 -1 ) states and the inner-valence 2 A 1 (4a 1 -1 ) state of the H 2 S + cation have also been dealt with. The occurrence of a peak at an energy below the excitation of the 2 A 1 (4a 1 -1 ) state and of various peaks associated to the (4a 1 -1 ) hole state in the photoelectron spectrum are discussed.

Theoretical study of molecular properties of low-lying electronic excited states of H2O and H2S

“…Minaev et al [28] and (SC) 2 -MR-SDCI (the size-consistent self-consistent dressing method [55]) values for singlets by Pitarch-Riuz et al [27] fairly correlate with our data as well. MR-DCI results of Petsalakis and…”

“…In Table 2 we presented just most recent ones [3,[15][16][17][18]. All of these [6,7,[22][23][24][25][26][27][28][29][30]. We present few most recent relevant data [23,[26][27][28] in Table 2.…”

“…All of these [6,7,[22][23][24][25][26][27][28][29][30]. We present few most recent relevant data [23,[26][27][28] in Table 2. The valence shell Hamiltonian calculations of Stevens et al [26] correlate very well with our CASPT2 and CCSD data.…”

Theoretical study of the valence and K‐shell spectra of atmospherically relevant CO2

“…The radial and angular contributions to the transition moment are then formulated, separately, as closed‐form analytic expressions. We find this analyticity to be one of the main advantages of the MQDO procedure, as all the calculations are free from numerical errors and convergence problems as shown in a number of recent studies 9–11.…”

Full configuration interaction calculation of BeH adiabatic states

“…This type of basis sets has proven reliable for the calculation of vertical excitation energies ͑VEEs͒ in a number of cases that involved Rydberg states. 67,[71][72][73][74][75] The basis set here described will be denoted as ANO1 + 4s4p2d when necessary. The 4s4p2d Rydberg AOs are reported in Table I.…”