scholarly journals Localized Orbital Corrections for the Barrier Heights in Density Functional Theory

2009 ◽  
Vol 5 (11) ◽  
pp. 2996-3009 ◽  
Author(s):  
Michelle Lynn Hall ◽  
Dahlia A. Goldfeld ◽  
Arteum D. Bochevarov ◽  
Richard A. Friesner
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Barrier Heights ◽  
Localized Orbital

scholarly journals Continuous Localized Orbital Corrections to Density Functional Theory: B3LYP-CLOC

2010 ◽  
Vol 6 (12) ◽  
pp. 3647-3663 ◽  
Author(s):  
Michelle Lynn Hall ◽  
Jing Zhang ◽  
Arteum D. Bochevarov ◽  
Richard A. Friesner
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Localized Orbital

DIRECT DENSITY FUNCTIONAL THEORY DYNAMICS STUDY FOR THE CH3OCF2CF2OCH3 + OH REACTION

2011 ◽  
Vol 10 (02) ◽  
pp. 231-244 ◽  
Author(s):  
HONG-BO YU ◽  
FENG-CHAO CUI ◽  
YONG-XIA WANG ◽  
HONG-XIA LIU ◽  
JING-YAO LIU
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Data ◽  
State Theory ◽  
Stationary Points ◽  
Enthalpies Of Formation ◽  
Oh Radicals ◽  
Isodesmic Reactions ◽  
Functional Theory ◽  
Barrier Heights

The mechanism and kinetics of the reaction of CH3OCF2CF2OCH3 with OH radicals have been studied theoretically by a direct density functional theory dynamics method. All possible H -abstraction channels and displacement processes taking place on two different conformers of CH3OCF2CF2OCH3 have been taken into consideration. The potential energy surface information including the optimized geometries and harmonic vibrational frequencies of all the stationary points and barrier heights involved in these channels were obtained at the BB1K/6-31+G(d,p) level of theory. The rate constants were calculated using improved canonical variational transition state theory (ICVT) with the small-curvature tunneling correction (SCT) over the temperature range of 200–2000 K. The overall rate constant for the title reaction, which was obtained by considering the weight factor of each conformer from the Boltzman distribution function, is in reasonable agreement with the available experimental value. Three-term Arrhenius expression is fitted to be k T = 1.56 × 10-20 T 2.47 exp (-124.64/ T ) cm 3 molecule-1 s-1 (200–2000 K). Also, the enthalpies of formation of the reactant CH3OCF2CF2OCH3 and product radicals CH3OCF2CF2OCH2 and CH3OCF2CF2O , which lack experimental or theoretical data, were evaluated via applying isodesmic reactions.

Multiconfiguration Pair-Density Functional Theory: Barrier Heights and Main Group and Transition Metal Energetics

2014 ◽  
Vol 11 (1) ◽  
pp. 82-90 ◽  
Author(s):  
Rebecca K. Carlson ◽  
Giovanni Li Manni ◽  
Andrew L. Sonnenberger ◽  
Donald G. Truhlar ◽  
Laura Gagliardi
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Density Functional ◽  
Main Group ◽  
Functional Theory ◽  
Barrier Heights ◽  
Pair Density

THE DISSOCIATION AND ISOMERIZATION REACTIONS OF N11 ISOMERS

2003 ◽  
Vol 02 (01) ◽  
pp. 15-22
Author(s):  
QIAN SHU LI ◽  
YONG DONG LIU
Keyword(s):  
Density Functional Theory ◽  
Barrier Height ◽  
Energy Barrier ◽  
Lower Energy ◽  
Density Functional ◽  
Functional Theory ◽  
Barrier Heights ◽  
The Density Functional Theory

The dissociation and isomerization reactions of N 11 isomers, including the two structures 1 and 3 previously studied as well as the three new structures 2, 4, and 5, were investigated by the density functional theory (DFT) at the B3LYP/6-31G(d), B3LYP/6-311G(d), and B3LYP/6-311+G(3df)//B3LYP/6-311G(d) levels of theory. The results indicate that, similar to previous results on N 9 and N 10 isomers, the barrier heights for structures 1 and 2 to lose N 2 are about 10–15 kcal/mol whereas the barrier heights for structures 1–3 to lose N 3 are about 25–30 kcal/mol. Therefore, it seems that N 2 is easier to be eliminated than is N 3 from the relatively larger nitrogen isomers. In addition, for structures 1 and 3, both dissociation and isomerization can occur in the N8–N9 bond, due partly to its character in having an aromatic bond. Moreover, the isomerization is preferred compared with dissociation because of its relatively lower energy barrier height.

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