Ab initio study of the electronic spectrum of C2H2+: Investigation of structure of spectra involving low-lying doublet electronic states

Abstract

A model electronic Hamiltonian to study low-lying electronic states of [Fe(bpy)3]2+ in aqueous solution J. Chem. Phys. 136, 064519 (2012); 10.1063/1.3684239Quantum chemical study of the electronic structure of NiCH 2 + in its ground state and low-lying electronic excited states Ab initio investigation of the vibronic spectrum involving the two lowest-lying electronic states of HCCO Ab initio calculated potential energy surfaces for low-lying doublet electronic states of C 2 H 2 ϩ are employed to investigate the structure of spectra involving these species. Particular attention is paid to the X 2 ⌸ u , A 2 A g , and B 2 ⌺ u ϩ states arising by loss of an electron from one of the three uppermost molecular orbitals populated in the ground electronic state of the neutral molecule.

Structure, Ionization, and Fragmentation of Neutral and Positively Charged Hydrogenated Carbon Clusters: CnHmq+ (n = 1–5, m = 1–4, q = 0–3)

“…In particular, geometries, simulated spectra, energies of their different species, and the rate of the possible reactions are crucial quantities in astrochemical modeling. In the last years there has been a large effort to provide such information for carbon clusters and hydrocarbon molecules, both in neutral and ionic states. ,− All these efforts converge into different databases such as the Kinetic Database for Astrochemistry (KIDA) …”

“…In the present article we studied in a systematic way the properties of neutral and positively charged hydrogenated carbon clusters following our previous theoretical studies for carbon clusters. − Previous theoretical studies have been performed for some of the neutral C n H m ,− and singly charged systems ,− considered in this work. For dications only very specific cases, such as acetylene dication, have been theoretically studied before, and one previous work for trications focuses on pure carbon clusters .…”

The Renner-Teller effect in HCCCl+(X̃2Π) studied by zero-kinetic energy photoelectron spectroscopy and ab initio calculations

“…7,14,[17][18][19][20][21][25][26][27][28][29] Here, we only provide a short description. The Hamiltonian of the molecule is expressed as…”

“…For HCCH + (X 2 Π), the rotationally resolved vibronic energy levels have been determined using high resolution photoelectron spectroscopy, [16][17][18] and the ab initio calculations have been found to be in good agreement with the experimental data. [19][20][21][22][23][24] However, there is no direct cross-mode vibronic coupling due to the inversion (i) symmetry. In the case of HCCS(X 2 Π), laser-induced fluorescence (LIF)Ã 2 Π ←X 2 Π, has been employed to measure its vibronic energy levels and has provided great insights into the RT effect in tetra-atomic molecules.…”

“…In comparison with many theoretical studies on HCCS (X 2 Π), HCCH + (X 2 Π), and HCCO(B 2 Π), [19][20][21][22][23][24][28][29][30] there are few theoretical studies about the RT effect in HCCCl + . Using the restricted Hartree-Fock (RHF) method in combination with empirical adjustments, the geometric structure of HCCCl + has been determined and the potential energy curves along the C≡ ≡C stretch, Cl-C stretch, and C-H stretch have been calculated.…”