AB initio calculation of the potential surfaces and minimum energy paths of intramolecular rearrangements I. Heterovalent isomerism in the system BOH?HBO

1979 ◽  
Vol 20 (1) ◽  
pp. 1-7 ◽  
Author(s):  
T. S. Zyubina ◽  
O. P. Charkin ◽  
L. V. Gurvich
Keyword(s):  
Ab Initio ◽  
Ab Initio Calculation ◽  
Minimum Energy ◽  
Potential Surfaces ◽  
Intramolecular Rearrangements ◽  
Minimum Energy Paths

Ab initio calculation of the potential surfaces for low-lying valence electronic states of the C2H radical

1989 ◽  
Vol 13 (4) ◽  
pp. 307-316 ◽  
Author(s):  
H. Thümmel ◽  
M. Perić ◽  
S. D. Peyerimhoff ◽  
R. J. Buenker
Keyword(s):  
Ab Initio ◽  
Ab Initio Calculation ◽  
Electronic States ◽  
Potential Surfaces ◽  
C2h Radical

Ab initio calculation of adiabatic potential surfaces for Ne*(2p53s,1,3P)+H2(1Σ+g)

1987 ◽  
Vol 87 (10) ◽  
pp. 6000-6003 ◽  
Author(s):  
B. Stern ◽  
J. Robert ◽  
J. Reinhardt ◽  
V. Bocvarski ◽  
J. Baudon
Keyword(s):  
Ab Initio ◽  
Ab Initio Calculation ◽  
Adiabatic Potential ◽  
Potential Surfaces

scholarly journals Effects of Aluminum on Hydrogen Solubility and Diffusion in Deformed Fe-Mn Alloys

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
C. Hüter ◽  
S. Dang ◽  
X. Zhang ◽  
A. Glensk ◽  
R. Spatschek
Keyword(s):  
Ab Initio ◽  
Equilibrium Model ◽  
Hydrogen Diffusion ◽  
Local Equilibrium ◽  
Minimum Energy ◽  
Trap Site ◽  
Elastic Band ◽  
Band Method ◽  
Minimum Energy Paths ◽  
And Diffusion

We discuss hydrogen diffusion and solubility in aluminum alloyed Fe-Mn alloys. The systems of interest are subjected to tetragonal and isotropic deformations. Based onab initiomodelling, we calculate solution energies and then employ Oriani’s theory which reflects the influence of Al alloying via trap site diffusion. This local equilibrium model is complemented by qualitative considerations of Einstein diffusion. Therefore, we apply the climbing image nudged elastic band method to compute the minimum energy paths and energy barriers for hydrogen diffusion. Both for diffusivity and solubility of hydrogen, we find that the influence of the substitutional Al atom has both local chemical and nonlocal volumetric contributions.

On the structure of S42+ and its formation from 2S2+•Ab initio SCF and CASSCF studies

1994 ◽  
Vol 72 (2) ◽  
pp. 298-303 ◽  
Author(s):  
Mousumi Sannigrahi ◽  
Friedrich Grein
Keyword(s):  
Transition State ◽  
Ab Initio ◽  
Minimum Energy ◽  
Vibrational Frequencies ◽  
Square Planar ◽  
Experimental Values ◽  
Minimum Energy Paths

Ab initio studies up to the MP2/6-31G* level were performed on the geometry and energy of S42+. Eleven different structures were considered. In the RHF/6-31G* method, the square structure is the most stable, followed by the trans-planar C2h structure. S42+ (square) is 105.9 kcal/mol less stable than 2S22+. Minimum energy paths were calculated for the reaction 2S2+ → S42+, both in C2v and D2h symmetry. Using RHF/6-31G*, the transition state lies about 50 kcal/mol above the energy of square planar S42+. Using CASSCF or MP2 methods this energy can be significantly lowered (to about 33 kcal/mol in MP2/6-31G*). Calculated vibrational frequencies for the square structure are also given and compared with experimental values.

An ab initio calculation of the vibronic energies of the CH2+ molecule

1994 ◽  
Vol 72 (11-12) ◽  
pp. 871-878 ◽  
Author(s):  
W. P. Kraemer ◽  
Per Jensen ◽  
P. R. Bunker
Keyword(s):  
Ab Initio ◽  
Electronic State ◽  
Ab Initio Calculation ◽  
Energy Levels ◽  
Morse Oscillator ◽  
Potential Surfaces ◽  
Complete Active Space ◽  
Consistent Field ◽  
Self Consistent Field ◽  
Linear Configuration

In this paper we report the results of an ab initio calculation of vibronic (i.e., N = 0) energy levels of the CH2+ molecular ion giving the lowest 19 levels of the ground [Formula: see text] electronic state and the lowest 15 of the first excited Ã2B1 state. The two electronic states become degenerate (2Π) at the linear configuration and their rovibronic levels interact via the Renner effect. The ab initio calculation of the two potential surfaces was performed at 96 nuclear geometries for the ground electronic state, covering energies up to 11 000 cm−1 above equilibrium, and at 86 geometries for the excited state, covering energies up to 30 000 cm−1 above equilibrium. The multireference configuration interaction (MRCI) level of theory was used with molecular orbital bases that were optimized separately for each state by complete-active-space-self-consistent-field (CASSCF) calculations. The vibronic energy levels were calculated variationally from the potential surfaces using the Morse oscillator rigid bender internal dynamics Hamiltonian modified to include the effects of the Renner interaction. We also present calculated vibronic energies for the CD2+ and CHD+ isotopically substituted molecules.

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