Chemical reaction dynamics of PeCB and TCDD decomposition: A tight‐binding quantum chemical molecular dynamics study with first‐principles parameterization

Abstract

ABSTRACT:The decomposition reaction dynamics of 2,3,4,4Ј,5-penta-chlorinated biphenyl (2,3,4,4Ј,3,3Ј,4,4Ј,3Ј,4,4Ј,and 2,3,7,3,7, was clarified for the first time at atomic and electronic levels, using our novel tight-binding quantum chemical molecular dynamics method with first-principles parameterization. The calculation speed of our new method is over 5000 times faster than that of the conventional firstprinciples molecular dynamics method. We confirmed that the structure, energy, and electronic states of the above molecules calculated by our new method are quantitatively consistent with those by first-principles calculations. After the confirmation of our methodology, we investigated the decomposition reaction dynamics of the above molecules and the calculated dynamic behaviors indicate that the oxidation of the 2,3,4,4Ј,5-PeCB, 3,3Ј,4,4Ј,5-PeCB, and 2,3,7,8-TCDD proceeds through an epoxide intermediate, which is in good agreement with the previous experimental reports and consistent with our static density functional theory calculations. These results proved that our new tight-binding quantum chemical molecular dynamics method with firstprinciples parameterization is an effective tool to clarify the chemical reaction dynamics at reaction temperatures.

Electronic structure and electrical conductivity of MgO protecting layer in plasma‐display panels: A tight‐binding quantum chemical study

“…Based on these results, we determined the charge dependency of ζ r of Mg 3s atomic orbital by using the polynomial functions of the atomic charges. 15 The parameters regarding the H rr term were similarly determined by using the DFT method for Mg 3s [ Fig. 3(b)].…”

“…The more-detailed explanation of the atomic-charge dependencies of the parameters are described in our previous paper. 15 The above parameterization enables us to precisely predict the electronic structure and chemical property of a given system.…”

Effect of the Titanium Nanoparticle on the Quantum Chemical Characterization of the Liquid Sodium Nanofluid

“…The suitability of quantum chemical parameters, H rr and ζ r for TBQC calculation was confirmed by comparing with several DFT results of ADF program and DMol 3 code. 14 According to the previously established first-principles parametrization procedure, 15 Figure 1a,b depict the respective radial distributions of electron density for the sodium (Na 3s and Na 3p) and titanium (Ti 3d, Ti 4s, and Ti 4p) atomic orbitals with neutral charge calculated by ADF program and TBQC programs. Applied single-ζ or the double-ζ basis sets of Slater type orbital of TBQC program are also noted in the caption.…”

Quantum chemistry and QSPR study on relationship between crystal structure and emission wavelength of Eu2+‐doped phosphors

“…Calculations were performed using our original program, Colors, [13][14][15][16][17][18][19][20] which is based on TB theory. The total energy E in our TB theory is defined as follows:…”

“…In our TB theory, the Hamiltonian H for an electronic system is constructed by using the parameters, which are determined by using first-principles calculations. [13][14][15][16][17][18][19][20] The parameter sets used in this study were the same in the manuscript: the electronic structure of BAM:Eu 2+ obtained by the TB-QC, with the parameter sets also in good agreement with that obtained by first-principles calculation. 12 The diagonal elements H rr were obtained by the function of the valence-state ionization potentials.…”