A density functional elongation method for the theoretical synthesis of aperiodic polymers

1994 ◽  
Vol 52 (2) ◽  
pp. 267-280 ◽  
Author(s):  
Yuriko Aoki ◽  
S�ndor Suhai ◽  
Akira Imamura
Keyword(s):  
Density Functional ◽  
Elongation Method ◽  
Theoretical Synthesis

Comparative theoretical synthesis of high-energy explosive 1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin

2014 ◽  
Vol 13 (05) ◽  
pp. 1450045 ◽  
Author(s):  
Ken-Fa Cheng ◽  
Min-Hsien Liu
Keyword(s):  
Density Functional ◽  
Raw Materials ◽  
Condensation Reaction ◽  
High Energy ◽  
Reaction Scheme ◽  
Base Function ◽  
Functional Theory ◽  
Compound A ◽  
Hartree Fock ◽  
Theoretical Synthesis

Reaction mechanisms were proposed in this study for the theoretical synthesis of high-energy 1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin (TNAD). Corresponding computations were performed using density functional theory (DFT) and the Hartree Fock (HF) method with the same 6-31G(d,p) base function. Glyoxal and ethylenediamine were used as the raw materials and were placed into respective gaseous and solvated (water or ethanol) environments to proceed the condensation reaction to form the precursor 1,4,5,8-tetraazadecalin, which subsequently underwent four stages of nitro-group substitution to obtain the target TNAD compound. A whole reaction scheme closely related to the experimental processes was successfully constructed, and the corresponding energy barriers were estimated for each elementary reaction. The findings revealed that the overall activation energy by B3LYP/6-31G(d,p) calculation is 2660.4 kJ/mol, which is lower than the 2832.1 kJ/mol calculated by HF/6-31G(d,p) computation. Furthermore, the reaction has a lower overall energy barrier in the solvated environment than in the gaseous system, being 2389.6 kJ/mol in ethanol, 2428.7 kJ/mol in water and 2660.4 kJ/mol in the gaseous phase. The ethanol-solvated system is suggested to be the most suitable medium for the synthesis of TNAD.

Doping effects on the geometric and electronic structure of tin clusters

2019 ◽  
Vol 21 (44) ◽  
pp. 24478-24488 ◽  
Author(s):  
Martin Gleditzsch ◽  
Marc Jäger ◽  
Lukáš F. Pašteka ◽  
Armin Shayeghi ◽  
Rolf Schäfer
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Beam Deflection ◽  
Functional Theory ◽  
Doping Effects ◽  
Depth Analysis ◽  
Trajectory Simulations

In depth analysis of doping effects on the geometric and electronic structure of tin clusters via electric beam deflection, numerical trajectory simulations and density functional theory.

What correlation effects are covered by density functional theory?

2000 ◽  
Vol 98 (20) ◽  
pp. 1639-1658 ◽  
Author(s):  
Yuan He, Jurgen Grafenstein, Elfi Kraka,
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Correlation Effects ◽  
Functional Theory

Accurate density functional thermochemistry for larger molecules

1997 ◽  
Vol 91 (3) ◽  
pp. 555-559 ◽  
Author(s):  
KRISHNAN RAGHAVACHARI ◽  
BORIS STEFANOV ◽  
LARRY CURTISS
Keyword(s):  
Density Functional

A hybrid Gaussian and plane wave density functional scheme

1997 ◽  
Vol 92 (3) ◽  
pp. 477-487 ◽  
Author(s):  
GERALD LIPPERT ◽  
JuRG HUTTER ◽  
MICHELE PARRINELLO
Keyword(s):  
Plane Wave ◽  
Density Functional ◽  
Functional Scheme
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