Accurate Prediction of Bond Dissociation Energies and Barrier Heights for High-Energy Caged Nitro and Nitroamino Compounds Using a Coupled Cluster Theory

2019 ◽  
Vol 123 (23) ◽  
pp. 4883-4890 ◽  
Author(s):  
Vitaly G. Kiselev ◽  
C. Franklin Goldsmith
2020 ◽  
Author(s):  
Xinghui Jin ◽  
Menghui Xiao ◽  
Jianhua Zhou ◽  
Bingcheng Hu

A series of 1,2,5-oxadiazole-1,2,3,4-tetrazole based high energy materials were theoretically designed and investigated. Their heats of formation, detonation properties and thermal stabilities were calculated by isodesmic reactions, Kamlet-Jacobs equations and bond dissociation energies, respectively. The results show that all the designed compounds possess high positive heats of formation and the –N=N–/–N3 substituents were found to be more helpful in improving the heats of formation than other substituents. The change tendency of densities, detonation pressures and detonation velocities were approximately the same to each other which suggests that values of densities were the key parameter to detonation properties rather than other parameters. In view of bond dissociation energies, the –CN/–NH2 substituents will be helpful to improve the thermal stabilities of the designed compounds while the other substituents/bridges will decrease their thermal stabilities to some extent. Take detonation properties and thermal stabilities into consideration, six compounds (C7, D3, D7, F7, G7 and H7) were selected as potential high energy density compounds since they had higher detonation properties and thermal stabilities than those of RDX. Finally, electronic structures (such as distribution of frontier molecular orbitals and electrostatic potentials) of the selected compounds were simulated to give a better understanding of these compounds.


Author(s):  
Yuhong Liu ◽  
Anthony Dutoi

<div> <div>A shortcoming of presently available fragment-based methods is that electron correlation (if included) is described at the level of individual electrons, resulting in many redundant evaluations of the electronic relaxations associated with any given fluctuation. A generalized variant of coupled-cluster (CC) theory is described, wherein the degrees of freedom are fluctuations of fragments between internally correlated states. The effects of intra-fragment correlation on the inter-fragment interaction is pre-computed and permanently folded into the effective Hamiltonian. This article provides a high-level description of the CC variant, establishing some useful notation, and it demonstrates the advantage of the proposed paradigm numerically on model systems. A companion article shows that the electronic Hamiltonian of real systems may always be cast in the form demanded. This framework opens a promising path to build finely tunable systematically improvable methods to capture precise properties of systems interacting with a large number of other systems. </div> </div>


2017 ◽  
Author(s):  
Yuhong Liu ◽  
Anthony Dutoi

<div> <div>A shortcoming of presently available fragment-based methods is that electron correlation (if included) is described at the level of individual electrons, resulting in many redundant evaluations of the electronic relaxations associated with any given fluctuation. A generalized variant of coupled-cluster (CC) theory is described, wherein the degrees of freedom are fluctuations of fragments between internally correlated states. The effects of intra-fragment correlation on the inter-fragment interaction is pre-computed and permanently folded into the effective Hamiltonian. This article provides a high-level description of the CC variant, establishing some useful notation, and it demonstrates the advantage of the proposed paradigm numerically on model systems. A companion article shows that the electronic Hamiltonian of real systems may always be cast in the form demanded. This framework opens a promising path to build finely tunable systematically improvable methods to capture precise properties of systems interacting with a large number of other systems. </div> </div>


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