Zhang Xian-Zhou

Computational study of imidazole derivative as high energetic materials

Density functional theory (DFT) calculations were performed for a series of imidazole derivatives. B3LYP and B3P86 functionals with 6-31G** basis set were used. Heats of formation (HOFs) were predicted through designed isodesmic reactions. Calculated results show that the HOFs relate to the number and the position of nitro groups. The HOFs increase with the augment of the number of the NO(2) group for the direct imidazole derivatives and decrease with the augment of the number of the NO(2) group for 1-picrylimidazole derivatives. Thermal stabilities were evaluated via bond dissociation energies (BDEs). The result shows that the increase of nitro group number on imidazole ring reduces the stability of the molecule. Further, the correlation was developed between impact sensitivity h(50) and the ratio (BDE/E) of the weakest bond BDE to the total energy E. The detonation performance data were also calculated.

Quantum key distribution series network protocol with M -classical Bobs

Secure key distribution among classical parties is impossible both between two parties and in a network. In this paper, we present a quantum key distribution (QKD) protocol to distribute secure key bits among one quantum party and numerous classical parties who have no quantum capacity. We prove that our protocol is completely robust, i.e., any eavesdropping attack should be detected with nonzero probability. Our calculations show that our protocol may be secure against Eves symmetrically individual attack.

Density Functional Theory Study of Several Nitrotriazole Derivatives

Quantum chemical calculations at B3LYP/6-31G* and B3P86/6-31G* levels are used to predict the bond dissociation energies (BDEs) of seven nitrotriazole derivatives. It is noted that the BDEs of the initial scission step are between 44 and 70 kcal/mol, which are larger than those of piperidine and diazocine compounds and polynitro benzoate molecules. In addition, substituent groups greatly affect the bond dissociation energies of the title compounds. The heats of formation (HOFs) for seven energetic materials are also calculated via designed isodesmic reactions. From computational results it is noted that substituent groups strongly affect the HOFs. The research demonstrated that the HOF of the compound substituted by a five-membered ring is larger than those substituted by a six-membered ring for 1,2,4-triazole. The detonation performance data of the title compounds are also calculated according to the HOFs calculated by B3LYP/6-31G* level.

Theoretical investigation on the non-linear optical properties, vibrational spectroscopy and frontier molecular orbital of (E)-2-cyano-3-(3-hydroxyphenyl)acrylamide molecule.

The vibrational frequencies of (E)-2-cyano-3-(3-hydroxyphenyl)acrylamide (HB-CA) in the ground state have been calculated using density functional method (B3LYP) with B3LYP/6-311++G(d,p) basis set. The analysis of natural bond orbital was also performed. The IR spectra were obtained and interpreted by means of potential energies distributions (PEDs) using MOLVIB program. In addition, the results show that there exists C-H⋯O hydrogen bond in the title compound, which is confirmed by the natural bond orbital analysis. The predicted NLO properties show that the title compound is a good candidate as nonlinear optical material. The analysis of frontier molecular orbitals shows that HB-CA has high excitation energies, good stability and high chemical hardness. The analysis of MEP map shows the negative and the positive potential sites.

Computational investigation of the heat of formation, detonation properties of furazan-based energetic materials

The heats of formation (HOFs) for a series of furazan-based energetic materials were calculated by density functional theory. The isodesmic reaction method was employed to estimate the HOFs. The result shows that the introductions of azo and azoxy groups can increase the HOF, but the introduction of azo group can increase the more HOF, when compared with azoxy group. The detonation velocities and detonation pressures of the furazan-based energetic materials are further evaluated at B3LYP/6-31G* level. Dioxoazotetrafurazan and azoxytetrafurazan may be regarded as the potential candidates of high-energy density materials because of good detonation performance. In addition, there are good linear correlations between OB and detonation velocities, and OB and detonation pressures. The energy gaps between the HOMO and LUMO of the studied compounds are also investigated. These results provide basic information for the molecular design of novel high-energy density materials.

Relativistic Quadrupole Polarizability for the Ground State of Hydrogen-Like Ions

The static quadrupole polarizabilities for hydrogen-like ions from Z = 1 to Z = 100 in the 1S(1/2) ground state are calculated to high precision by solving the Dirac equation using the B-spline Galerkin method. The results are consistent with the expression of Kaneko [J. Phys. B 10 (1977) 3347] at low Z. The quadrupole oscillator strength sum Sigma(n) f(gn)((2)) is computed to be zero to a very high degree of precision.

Theoretical investigation on crystal structure, detonation performance and thermal stability of a high density cage hexanitrohexaazaisowurtzitane derivative

AbstractDensity functional theory calculations were performed to study the new polynitro cage compound with the similar framework of HNIW. IR spectrum, heat of formation and thermodynamic properties were predicted. The bond dissociation energies and bond orders for the weakest bonds were analysed to investigate the thermal stability of the title compound. The detonation and pressure were evaluated by using the Kamlet–Jacobs equations based on the theoretical density and condensed HOFs. In addition, the results show that there exists an essentially linear relationship between the WBIs of N–NO2 bonds and the charges –QNO2 on the nitro groups. The crystal structure obtained by molecular mechanics belongs to P21/C space group, with lattice parameters Z = 4, a = 12.3421 Å, b = 24.6849 Å, c = 20.4912 Å, ρ = 1.896 g cm − 3. The designed compound has high thermal stability and good detonation properties and is a promising high energy density compound. Graphical AbstractThe IR spectrum, heat of formation and thermodynamic properties of a new polynitro cage compound were calculated by theoretical method. The results show that the obtained crystal structure belongs to P21/C space group. There exists a good linear relationship between the WBIs of N-NO2 bonds and the charges –QNO2.

Theoretical studies on a series of 1,2,4-triazoles derivatives as potential high energy density compounds

AbstractDensity functional theory calculations at B3LYP/6-31G** and B3P86/6-31G** levels were performed to predict the densities (ρ), detonation velocities (D), pressures (P) and the thermal stabilities for a series of 1,2,4-triazole derivatives for looking high energy density compounds (HEDCs). The heats of formation (HOFs) are also calculated via designed isodesmic reactions. The calculations on the bond dissociation energies (BDEs) indicate that the position of the subsitutent group has great effect on the BDE and the BDEs of the initial scission step are between 31 and 65 kcal/mol. In addition, the condensed phase heats of formation are also calculated for the title compounds. These results would provide basic information for further studies of HEDCs. Graphical AbstractDensities, detonation velocities and pressures for a series of 1,2,4-triazole derivatives, as well as their thermal stabilities, were investigated to look for high energy density compounds (HEDCs). Heats of formation (HOFs) were also calculated via designed isodesmic reactions. 5,5′-Dinitro-3,3′-bi-1,2,4-triazole, 3-nitro-1-picryl-1,2,4-triazole and 4-(2,4-dinitrobenzyl)-3,5-dinitro-1,2,4-triazole satisfy the quantitative standard of HEDC.

Coherent Control of Molecular Alignment and Orientation by a Femtosecond Two-Color Laser Pulse

The coherent control of molecular alignment and orientation by a femtosecond two-color laser pulse is studied theoretically. The effect of the carrier-envelope phase of the femtosecond two-color laser pulse on molecular alignment and orientation is discussed, and it is shown that the enhancement or suppression of the molecular orientation can be coherently manipulated by precisely controlling the carrier-envelope phase of the femtosecond two-color laser pulse. In addition, the time-dependent angular distributions of the molecular axis are presented.

First-Principles Calculations of Elastic and Thermal Properties of Lanthanum Hexaboride

The plane-wave pseudopotential method using the generalized gradient approximation within the framework of density functional theory is applied to anaylse the bulk modulus, thermal expansion coefficient and heat capacity of LaB6. The quasi-harmonic Debye model, using a set of total energy versus volume obtained with the plane-wave pseudopotential method, is applied to the study of the thermal properties and vibrational effects. We analyse the bulk modulus of LaB6 up to 1500 K. The elastic properties calculations show that our system is mechanically stable. For the heat capacity and the thermal expansion, significant differences in properties are observed above 300K. The calculated zero pressure bulk modulus is in good agreement with the experimental data. Moreover, the Debye temperatures are determined from the non-equilibrium Gibbs functions and compared to available data.