Excited states and photochemistry of saturated molecules. The vibrational structure in the electronic spectrum of ethane

Ab initio SCF and CI calculations for the potential surfaces of HCN in ground and various 1(π,π*) excited states are carried out using an AO basis of double-zeta quality augmented with various polarization functions. These results are then combined with transition moment data to allow for a Franck-Condon analysis of the vibrational structure of the lowest three electronic transitions in both HCN and DCN. The resulting intensity distribution is then compared with the corresponding experimental data reported by Herzberg and Innes. This work confirms the earlier conclusion of Schwenzer et al. that the upper state in the [Formula: see text] band system is the 1∑−−1A″species, and not the 1Δ as originally believed. In addition a detailed mechanism for the observed predissociation of the α state is outlined, in which the gradual conversion of the π* MO of bent HCN into a pure hydrogenic 1s AO plays a key role. Arguments are also presented in favor of assigning the [Formula: see text]transition seen in DCN to a 1Δ-21A′ upper state with the same D + CN dissociation limit as for the 1∑−−1A″ species.

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The Electronic Spectrum and Structure of Tetrasulfur Dinitride

Zeitschrift für Naturforschung A ◽

10.1515/zna-1983-0114 ◽

1983 ◽

Vol 38 (1) ◽

pp. 74-77 ◽

Cited By ~ 4

Author(s):

Michael H. Palmer

Keyword(s):

Molecular Structure ◽

Ab Initio ◽

Electronic Spectrum ◽

Excited States ◽

Configuration Interaction ◽

Configuration Interaction Calculations ◽

Single Configuration ◽

Virtual Orbitals

Abstract Ab initio configuration interaction calculations of the ground and singlet A′ and A″ excited states have been performed, with all possible single and double excitations from the 10 highest occupied orbitals to the lowest 17 virtual orbitals being included, the previous Cs symmetry molecular structure being used. Some of the states can be identified with excitation from individual occupied (SCF) orbitals to members of the virtual set, but some are not well represented by single configuration concepts. The results suggest that the three broad UV-spectral maxima observed in solution are not single excitations, but groups of excited states, with a total of 8 states. The closeness of some of these states makes positive assignment difficult. The most probable assignment is 455 nm (1 A″), 377 nm (2A″ + 1A′+ 2A′), ~ 277 nm (3A″ + 3A′), 232 nm (4A′ + 4A″).

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Molecular and Vibrational Structure of Tetroxo d0Metal Complexes in their Excited States. A Study Based on Time-Dependent Density Functional Calculations and Franck–Condon Theory

The Journal of Physical Chemistry A ◽

10.1021/jp212292j ◽

2012 ◽

Vol 116 (7) ◽

pp. 1864-1876 ◽

Cited By ~ 16

Author(s):

Linta Jose ◽

Michael Seth ◽

Tom Ziegler

Keyword(s):

Excited States ◽

Density Functional Calculations ◽

Density Functional ◽

Vibrational Structure ◽

Time Dependent ◽

Franck Condon ◽

Dependent Density

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Ab initio study of the electronic spectrum of BeO

Journal of the Serbian Chemical Society ◽

10.2298/jsc9912721a ◽

1999 ◽

Vol 64 (12) ◽

pp. 721-735 ◽

Cited By ~ 2

Author(s):

Ivana Adamovic ◽

Maja Parac ◽

Michael Hanrath ◽

Miljenko Peric

Keyword(s):

Energy Range ◽

Ab Initio ◽

Electronic Spectrum ◽

Quantum Chemical ◽

Electronic States ◽

Vibrational Structure ◽

Ab Initio Method ◽

Ab Initio Study

Low-lying singlet and triplet electronic states of the BeO molecule are calculated by means of the quantum chemical ab initio method. It was found that all states in the energy range from 0 to 50000 cm-1 are of valence character. Particular attention was paid to the investigation of the dissociative behavior of the states considered. The vibrational structure of the A 1P ? X1S and B 1S+ ? X1S+ spectral systems was calculated.

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