Relaxed structure of typical nitro explosives in the excited state: observation, implication and application

2017 ◽  
Author(s):  
Genbai Chu ◽  
Zuhua Yang ◽  
Tao Xi ◽  
Jianting Xin ◽  
Yongqiang Zhao ◽  
...  
Keyword(s):  
Excited State ◽  
Excitation Energy ◽  
Density Functional ◽  
Energetic Material ◽  
Functional Theory ◽  
State Observation ◽  
Lower Excitation Energy ◽  
Nitro Explosives ◽  
Lower Excitation ◽  
Insight Into

<a></a><a></a><a></a><a>U</a><a></a><a></a><a></a><a></a><a></a><a>nderstanding the structural, geometrical and chemical changes that occur after electronic excitation is essential to unraveling the inherent mechanism of nitro explosives. In this work, relaxed structures of typical nitro explosives in the excited state are investigated by time-dependent density functional theory. During the excitation process, nitro group becomes activated and then relaxes, leading to a relaxed structure. </a><a></a><a>All five nitro explosives exhibit a similar behavior, and impact sensitivity is related to excitation energy of relaxed structure.</a> <a></a><a>H</a>igh sensitivity d-HMX has a lower excitation energy for relaxed structure than b-HMX. This work offers a novel insight into energetic material.<a></a>

Relaxed structure of typical nitro explosives in the excited state: observation and implication

2017 ◽  
Author(s):  
Genbai Chu
Keyword(s):  
Excited State ◽  
Excitation Energy ◽  
Nitro Group ◽  
Density Functional ◽  
Functional Theory ◽  
Chemical Mechanisms ◽  
State Observation ◽  
Nitro Explosives ◽  
Physical And Chemical ◽  
Insight Into

<a></a><a></a><a></a><a>U</a><a></a><a></a><a></a><a></a><a></a><a>nderstanding the structural, geometrical and chemical changes that occur after electronic excitation is essential to unraveling the inherent physical and chemical mechanisms of nitro explosives. In this work, the relaxed structure of some typical nitro explosives in the excited state, including RDX, HMX, CL-20, PETN and LLM-105, have been investigated by time-dependent density functional theory. During the excitation process, an electron is vertically excited into a low-lying excited state, imparting π-antibonding character onto the nitro group. The nitro group becomes activated by the excitation energy and then relaxes via vibrational cooling, leading to a relaxed excited-state structure. </a><a></a><a>All five nitro explosives exhibit similar behavior in which impact sensitivity is related to the excitation energy of the relaxed structure.</a> <a></a><a>Insight into the relaxed structure of typical nitro explosives offers an efficient method of unraveling ultrafast and complex photo-initiated reactions and detonation physics</a>.

Relaxed structure of typical nitro explosives in the excited state: observation and implication

2017 ◽  
Author(s):  
Genbai Chu
Keyword(s):  
Excited State ◽  
Excitation Energy ◽  
Nitro Group ◽  
Density Functional ◽  
Functional Theory ◽  
Chemical Mechanisms ◽  
State Observation ◽  
Nitro Explosives ◽  
Physical And Chemical ◽  
Insight Into

<a></a><a></a><a></a><a>U</a><a></a><a></a><a></a><a></a><a></a><a>nderstanding the structural, geometrical and chemical changes that occur after electronic excitation is essential to unraveling the inherent physical and chemical mechanisms of nitro explosives. In this work, the relaxed structure of some typical nitro explosives in the excited state, including RDX, HMX, CL-20, PETN and LLM-105, have been investigated by time-dependent density functional theory. During the excitation process, an electron is vertically excited into a low-lying excited state, imparting π-antibonding character onto the nitro group. The nitro group becomes activated by the excitation energy and then relaxes via vibrational cooling, leading to a relaxed excited-state structure. </a><a></a><a>All five nitro explosives exhibit similar behavior in which impact sensitivity is related to the excitation energy of the relaxed structure.</a> <a></a><a>Insight into the relaxed structure of typical nitro explosives offers an efficient method of unraveling ultrafast and complex photo-initiated reactions and detonation physics</a>.

Molecular Modelling of Ground- and Excited-States Vibrations in Organic Conducting Devices: Hexakis(n-hexyloxy)triphenylene (HAT6) as Case Study

2010 ◽  
Vol 63 (3) ◽  
pp. 388 ◽  
Author(s):  
M. Zbiri ◽  
M. R. Johnson ◽  
L. Haverkate ◽  
F. M. Mulder ◽  
G. J. Kearley
Keyword(s):  
Excited State ◽  
Electronic State ◽  
Ground State ◽  
Density Functional ◽  
Excited Electronic State ◽  
Molecular Vibrations ◽  
Functional Theory ◽  
Model Calculations ◽  
Insight Into

In order to gain insight into fundamental aspects of organic photocell materials, we have calculated ground and excited electronic-state structures and molecular vibrations for an isolated HAT6 molecule (hexakis(n-hexyloxy)triphenylene). Excited-state calculations are carried out using time-dependent density functional theory and frequencies are evaluated analytically using coupled perturbed Kohn–Sham equations. These model calculations have been validated against new infrared and ultraviolet data on HAT6 in solution. The main allowed valence excitation, having the largest oscillator strength, is chosen for the structural and vibrational investigations. Comparison with the ground-state vibrational dynamics reveals surprisingly large spectral differences. In addition, the alkoxy tails, which are usually considered to play only a structural role, are clearly involved in the molecular vibrations and the structural distortion of the excited electronic state compared with the ground state. The tails may play a more important role in charge separation, transport and excited-state relaxation than was previously thought. In this case, chemical modification of the tails would allow vibrational and related properties of organic photocell materials to be tailored.

Graphyne and graphdiyne: theoretical insight into ground and excited state properties

RSC Advances ◽  
2016 ◽  
Vol 6 (92) ◽  
pp. 89934-89939 ◽  
Author(s):  
Siddheshwar Chopra
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Density Functional ◽  
Time Dependent ◽  
Functional Theory ◽  
Carbon Allotropes ◽  
Theoretical Insight ◽  
Insight Into ◽  
Dependent Density

The ground and excited state properties of the two carbon allotropes, graphyne (C66H18) (gr1) and graphdiyne (C90H18) (gr2), in the form of nanoflakes were studied with the help of density functional theory (DFT) and time dependent density functional theory (TDDFT).

scholarly journals Ground- and excited-state characteristics in photovoltaic polymer N2200

RSC Advances ◽  
2021 ◽  
Author(s):  
Guanzhao Wen ◽  
Xianshao Zou ◽  
Rong Hu ◽  
Jun Peng ◽  
Zhifeng Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Excited State ◽  
Steady State ◽  
Excited States ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Time Dependent ◽  
Functional Theory ◽  
Time Resolved ◽  
Dependent Density

Ground- and excited-states properties of N2200 have been studied by steady-state and time-resolved spectroscopies as well as time-dependent density functional theory calculations.

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