scholarly journals Calculating the Symmetry Number of Flexible Sphere Clusters

2019 ◽  
Vol 29 (5) ◽  
pp. 2021-2053
Author(s):  
Emilio Zappa ◽  
Miranda Holmes-Cerfon
Keyword(s):  
Symmetry Number

scholarly journals Advances in Automated Transition State Theory Calculations: Improvements on the AutoTST Framework

2020 ◽  
Author(s):  
Nathan Harms ◽  
Carl Underkoffler ◽  
Richard West
Keyword(s):  
Transition State ◽  
Kinetic Parameters ◽  
Transition State Theory ◽  
Vibrational Analysis ◽  
Chemical Kinetic ◽  
State Theory ◽  
Combustion Chemistry ◽  
Transition State Geometry ◽  
Substantial Progress ◽  
Symmetry Number

<div>Kinetic modeling of combustion chemistry has made substantial progress in recent years with the development of increasingly detailed models. However, many of the chemical kinetic parameters utilized in detailed models are estimated, often inaccurately. To help replace rate estimates with more accurate calculations, we have developed AutoTST, an automated Transition State Theory rate calculator. This work describes improvements to AutoTST, including: a systematic conformer search to find an ensemble of low energy conformers, vibrational analysis to validate transition state geometries, more accurate symmetry number calculations, and a hindered rotor treatment when deriving kinetics. These improvements resulted in location of transition state geometry for 93% of cases and generation of kinetic parameters for 74% of cases. Newly calculated parameters agree well with benchmark calculations and perform well when used to replace estimated parameters in a detailed kinetic model of methanol combustion.</div>

scholarly journals Anatomical Variations of Foramen Transversarium of 7th Cervical Vertebrae and Its Clinical Significance

2020 ◽  
Vol 11 (3) ◽  
pp. 4902-4907
Author(s):  
Manoj P Ambali ◽  
Surekha D Jadhav
Keyword(s):  
Clinical Significance ◽  
Cervical Vertebrae ◽  
Anatomical Variations ◽  
Different Types ◽  
Cervical Approach ◽  
Present Evaluation ◽  
Symmetry Number ◽  
Over The Top

Cervical vertebrae have a cardinal part that is a closeness of and through it passes the vertebral course, vertebral vein and sharp plexus of nerves. The vertebral course enters the of C6 and this way, the FT of C7, which transmits just the vein and nerve, might be near nothing or even occasionally absent. A vertebral channel may enter through C7 in 2% cases as necessities be combinations of this may affect the anatomical course of vascular and neural structures, and this way may cause over the top conditions. The explanation behind the investigation was to watch the anatomical mixes in the of seventh cervical vertebrae. Present work was carried on 156 dry seventh cervical vertebrae of cloud sex and age. We observed each for shape, symmetry, number or accessory and spicules. We observed nine different types of shape of . Round shapes of were present in 28.75 %, accessory in 28.84% and spicules in 12.17 % of vertebrae also noted incomplete FT in 5 vertebrae. Disclosures of present evaluation may be helpful for a radiologist in the comprehension of X-segments, dealt with and scans for spine specialists in preoperative arranging and for blocking injury of a vertebral vessel near to sharp nerves during the careful cervical approach.

scholarly journals The symmetry number problem for trees

2001 ◽  
Vol 79 (2) ◽  
pp. 73-79 ◽  
Author(s):  
Kien-Weh Chin ◽  
Hsu-Chun Yen
Keyword(s):  
Number Problem ◽  
Symmetry Number

scholarly journals Advances in Automated Transition State Theory Calculations: Improvements on the AutoTST Framework

2020 ◽  
Author(s):  
Nathan Harms ◽  
Carl Underkoffler ◽  
Richard West
Keyword(s):  
Transition State ◽  
Kinetic Parameters ◽  
Transition State Theory ◽  
Vibrational Analysis ◽  
Chemical Kinetic ◽  
State Theory ◽  
Combustion Chemistry ◽  
Transition State Geometry ◽  
Substantial Progress ◽  
Symmetry Number

<div>Kinetic modeling of combustion chemistry has made substantial progress in recent years with the development of increasingly detailed models. However, many of the chemical kinetic parameters utilized in detailed models are estimated, often inaccurately. To help replace rate estimates with more accurate calculations, we have developed AutoTST, an automated Transition State Theory rate calculator. This work describes improvements to AutoTST, including: a systematic conformer search to find an ensemble of low energy conformers, vibrational analysis to validate transition state geometries, more accurate symmetry number calculations, and a hindered rotor treatment when deriving kinetics. These improvements resulted in location of transition state geometry for 93% of cases and generation of kinetic parameters for 74% of cases. Newly calculated parameters agree well with benchmark calculations and perform well when used to replace estimated parameters in a detailed kinetic model of methanol combustion.</div>

Additivity of Absolute Entropies

2004 ◽  
Vol 69 (1) ◽  
pp. 213-230 ◽  
Author(s):  
Ivan Černušák ◽  
Susan K. Gregurick ◽  
Marjorie Roswell ◽  
Carol A. Deakyne ◽  
H. Donald Brooke Jenkins ◽  
...  
Keyword(s):  
Diatomic Molecules ◽  
Symmetry Number

Symmetry number-corrected entropies for a series of inorganic diatomic molecules were analyzed. We have considered molecules XY (X, Y = H, F, Cl, Br, I, Li, Na, K, Rb, Cs, B and Al). Based on the assumption of elemental additivity, the prediction of known entropy data is quite satisfactory (except for H2) and provides fairly reasonable estimates for data currently unavailable.

Symmetry Number

2016 ◽  
Author(s):  
Keith J. Laidler
Keyword(s):  
Symmetry Number

The Entropy of Polyatomic Molecules and the Symmetry Number

1933 ◽  
Vol 55 (1) ◽  
pp. 37-53 ◽  
Author(s):  
Joseph E. Mayer ◽  
Stephen Brunauer ◽  
Maria Goeppert Mayer
Keyword(s):  
Polyatomic Molecules ◽  
Symmetry Number
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