ABOUT THE PRIMARY ACT OF PHOTOCHEMICAL DECOMPOSITION REACTIONS OF MONOSUBSTITUTED COBALTIHEXAMINE IONS

1960 ◽  
Vol 38 (12) ◽  
pp. 2373-2379 ◽  
Author(s):  
Z. Simon

We will discuss the primary act of photochemical decomposition of Co(NH3)5Xn+ ions in aqueous solution. The potential energy surfaces are plotted correlating the complex ion's energy levels with those of the decomposition products. For this purpose spectral and kinetic data are used, as well as Wigner–Witmer correlation rules. The potential energy surfaces and certain rules regarding the radiationless transitions between them permit us to draw certain qualitative conclusions concerning these decompositions. Our conclusions seem to be confirmed by available experimental data.

2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
Faina Dubnikova ◽  
Assa Lifshitz

Potential energy surfaces for three unimolecular elimination reactions: , , and were calculated using a variety of quantum chemical methods. It was shown that, in all the three cases, the transition state in the first step of the reaction leads to the production of the complex intermediates based on van der Waals interactions. In addition to the fact that the three complexes appear as intermediates on the potential energy surfaces, which means that they are not free entities, the entropy values of the two elimination products are far above those of the complexes due to their additional Sackur-Tetrode entropy. Moreover, the three vibrational frequencies of the H2O group in the (CH3)3COH complex and the H–Cl and H–F stretch frequencies in CH3CF3 and CH3CH2CH2Cl are quite different (see the various tables). The energy levels of the complexes were found to be below those of the corresponding decomposition products. Rate constants for the elimination processes were calculated from the potential energy surfaces using transition-state theory and were compared to available experimental data.


1986 ◽  
Vol 51 (10) ◽  
pp. 2057-2062 ◽  
Author(s):  
Jan Vojtík ◽  
Vladimír Špirko ◽  
Per Jensen

The present publication reports variational calculations of the vibrational energy levels for H3+, D3+, 6Li3+, and 7Li3+, starting from potential energy surfaces generated by the DIM scheme. The vibrational energies obtained agree semiquantitatively with those based on the best ab initio potentials available. The results seem to indicate that an analogous approach might be useful in describing the vibrational motion of heavier alkali cluster cations A3+.


2012 ◽  
Vol 11 (06) ◽  
pp. 1175-1182 ◽  
Author(s):  
RONG CHEN ◽  
HUA ZHU

We report averaged potential energy surfaces for isotopic Ne–CO2 complexes (20 Ne –13 C 16 O 2, 22 Ne –12 C 16 O 2 and 22 Ne –13 C 16 O 2). According to the latest ab initio potential of 20 Ne –12 C 16 O 2 (Chen R, Jiao EQ, Zhu H, Xie DQ, J Chem Phys133:104302, 2010) including the Q3 normal mode for the υ3 antisymmetric stretching vibration of the CO2 molecule. We obtain the averaged potentials for 20 Ne –13 C 16 O 2, 22 Ne –12 C 16 O 2 and 22 Ne –13 C 16 O 2 by the integration of the three-dimensional potential over the Q3 coordinate. The averaged potential surfaces are found to have a T-shaped global minimum and two equivalent linear local minima. The radial DVR/angular FBR method and the Lanczos algorithm are applied to calculate the rovibrational energy levels. Comparison with the available observed values showed an overall excellent agreement for all spectroscopic parameters and the microwave spectra.


2014 ◽  
Vol 670-671 ◽  
pp. 235-239
Author(s):  
Rong Chen ◽  
Xiao Ling Luo

Averaged potential energy surfaces for isotopic Ne–CO2complexes (20Ne–18O13C16O,20Ne–17O12C16O and22Ne–17O12C16O) are presented. According to the latestab initiopotential of20Ne–12C16O2(R. Chen, H. Zhu, D. Q. Xie, J. Chem. Phys, 133, 2010, 104302,) which incorporates its dependence on theQ3normal mode for the antisymmetric stretching vibration of the CO2molecule, we obtain the averaged potentials for20Ne–18O13C16O,20Ne–17O12C16O and22Ne–17O12C16O complexes by integrating the potential energy surface overQ3normal mode. Each averaged potential surfaces are found to have a T-shaped global minimum and two equivalent linear local minima. The radial DVR/angular FBR method and the Lanczos algorithm are applied to calculate the rovibrational energy levels. Comparison with the available experimental values showed an overall excellent agreement for all spectroscopic parameters and the microwave spectra.


Author(s):  
Zachary Morrow ◽  
Hyuk-Yong Kwon ◽  
Carl Tim Kelley ◽  
Elena Jakubikova

Molecular dynamics simulations often classically evolve the nuclear geometry on adiabatic potential energy surfaces (PESs), punctuated by random hops between energy levels in regions of strong coupling, in an algorithm...


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Haitao Ma ◽  
Chunfang Zhang ◽  
Zhijun Zhang ◽  
Xiaojun Liu ◽  
Wensheng Bian

New ab initio potential energy surfaces (PESs) for the two lowest-lying singlet 11A′ and 11A′′ electronic states of CH2, coupled by the Renner-Teller (RT) effect and meant for the spectroscopic study, are presented. The surfaces are constructed using a dual-level strategy. The internally contracted multireference configuration interaction calculations with the Davidson correction, using the aug-cc-pVQZ basis set, are employed to obtain 3042 points at the lower level. The core and core-valence correlation effects are taken into account in the ab initio calculations with a modified optimized aug-cc-pCVQZ basis set for the higher-level points. The analytical representations of these PESs, with the inclusion of the nonadiabatic RT terms, are obtained by the nonlinear least-squares fit of the calculated points to three-body expansion. Quantum dynamical calculations are performed on these PESs, and the computed vibronic energy levels for the two singlet electronic states are in excellent agreement with experiment.


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