TY - JOUR
T1 - Ab initio calculations on the excited states of π-systems. II. Valence excitations in diacetylene
AU - Karpfen, Alfred
AU - Lischka, Hans
N1 - Funding Information:
This work was supported by the Austrian “Fonds zur Fijrderungd er wissenschaftlicheFno r-schung”,P rojectN o. P4965.S upplyw ith ~mputer time by the “Interuniversit‘&resE DV Zentrum” Vienna is gratefullya cknowledged.
PY - 1986/2/15
Y1 - 1986/2/15
N2 - The electronic ground state and the first valence excited states of diacetylene (3Σ+u, 1,3Δu, 1,3Σ-u) are investigated with the aid of ab initio methods applying basis sets of double-zeta and triple-zeta + d quality. SCF, SCF CI, and MC SCF CI methods have been applied. We report equilibrium geometries, vertical and adiabatic excitation energies, and discuss two-dimensional bending potentials in detail. Both C2h- and C2v-type structures are considered. For the lowest singlet states harmonic vibrational analysis of totally symmetric modes has been carried out. Previous experimental assignments of singlet excited states of diacetylene are essentially confirmed in this study and new results on the energetics of triplet excited states are reported.
AB - The electronic ground state and the first valence excited states of diacetylene (3Σ+u, 1,3Δu, 1,3Σ-u) are investigated with the aid of ab initio methods applying basis sets of double-zeta and triple-zeta + d quality. SCF, SCF CI, and MC SCF CI methods have been applied. We report equilibrium geometries, vertical and adiabatic excitation energies, and discuss two-dimensional bending potentials in detail. Both C2h- and C2v-type structures are considered. For the lowest singlet states harmonic vibrational analysis of totally symmetric modes has been carried out. Previous experimental assignments of singlet excited states of diacetylene are essentially confirmed in this study and new results on the energetics of triplet excited states are reported.
UR - http://www.scopus.com/inward/record.url?scp=0001895897&partnerID=8YFLogxK
U2 - 10.1016/0301-0104(86)85120-5
DO - 10.1016/0301-0104(86)85120-5
M3 - Article
AN - SCOPUS:0001895897
SN - 0301-0104
VL - 102
SP - 91
EP - 102
JO - Chemical Physics
JF - Chemical Physics
IS - 1-2
ER -