We investigate the differential cross sections （DCS） of elastic electron scattering from CH4, CF4 and SF6 at six impact energies in a range of 100 700eV by employing the independent atom model （IAM） together with ...We investigate the differential cross sections （DCS） of elastic electron scattering from CH4, CF4 and SF6 at six impact energies in a range of 100 700eV by employing the independent atom model （IAM） together with the relativistic partial waves. The atom is present in an optical potential which is complex, spherically symmetric, and energy dependent. The optical potential of the atom is the sum of the direct static, dynamic polarization, local exchange and modified absorption potentials. The results obtained by using a modified absorption potential show significant improvements on the unmodified absorption potential results. The present results are generally in good agreement with experimental data available. In addition, the present results indicate that the structure of molecule manifests the observable effects on electron- molecule scattering.展开更多
The potential acting on an electron within a molecule (PAEM) is formulated, and then calculated using the ab initio MELD program plus a separate calculation program in the RHF molecular orbital theory, finally the thr...The potential acting on an electron within a molecule (PAEM) is formulated, and then calculated using the ab initio MELD program plus a separate calculation program in the RHF molecular orbital theory, finally the three-dimensional graphs of the potentials have been drawn. We have systematically investigated this kind of the potentials for a series of the diatomic molecules, such as HF, HCl, HBr, LiF, LiCl, and so on. The three-dimensional graph can clearly display the variation of the potential felt by an electron within a molecule and get a deeper understanding of the electronic motion and chemical bonding within a molecule.展开更多
A new approach to calculate the potential acting on an electron in a molecule（PAEM） has been established for drawing the molecular face（MF） of a macromolecule, according to the classic point charge model and the a...A new approach to calculate the potential acting on an electron in a molecule（PAEM） has been established for drawing the molecular face（MF） of a macromolecule, according to the classic point charge model and the atom-bond electronegativity equalization method（ABEEMσπ） for one electron in a molecule. We introduced a dy- namic charge distribution from the view of a local electron movement in a molecule based on the new approach, and as further direct evidence, we calculated some physical quantities using the original ab initio method and the new method to verify the accuracy of the method, such as the boundary distance（BD）, molecular face surface area（MFSA） and molecular reactivities indicated by the MFs for a variety of organic molecules. All the results by the new method are in agreement with the results by ab initio method.展开更多
The molecular intrinsic characteristic contour (MICC) is defined based on the clas-sical turning point of electron movement in a molecule. Three typical organic molecules, i.e. methane, methanol and formic acid, were ...The molecular intrinsic characteristic contour (MICC) is defined based on the clas-sical turning point of electron movement in a molecule. Three typical organic molecules, i.e. methane, methanol and formic acid, were employed as examples for detailed introduction of our method. Investigations on the cross-sections of MICC provide important information about atomic size changing in the process of forming molecules. The electron density distributions on the MICCs of these molecules were calculated and shown for the first time. Results showed that the electron density distribution on the MICC correlates closely with molecular chemical properties, and it provides a new insight into molecular boundary.展开更多
By utilizing the classical turning point of the electron movement, we have defined and computed the mo-lecular intrinsic characteristic contour (MICC) via the com-bination of the ab initio quantum chemistry computatio...By utilizing the classical turning point of the electron movement, we have defined and computed the mo-lecular intrinsic characteristic contour (MICC) via the com-bination of the ab initio quantum chemistry computational method with the ionization potential measured by photo-electron spectroscopy experiment. In this paper, we calcu-lated the MICCs of several small organic molecules contain-ing oxygen atom for the first time. The three-dimensional pictures have been drawn, by performing a large number of calculations. The analysis on some characterized cross-sec-tions of the MICC can provide atomic spatial changing information in the process of forming a molecule.展开更多
The potential felt by a single electron within a molecule represents the total interaction energy of this electron with all nuclei and the rest electrons in the molecule and is an important quantity. It is formulated ...The potential felt by a single electron within a molecule represents the total interaction energy of this electron with all nuclei and the rest electrons in the molecule and is an important quantity. It is formulated and then calculated by using the ab initio MELD program plus a separate calculation program. We have systematically investigated and discussed this kind of potentials for a series of molecules. In terms of the three dimensional graph, the variation of the potential acting on the single electron within a molecule has clearly and visually been shown, and hence the electronic movement and the chemical bonding can be deeply understood.展开更多
The nature of halogen bonding in five complexes formed between the thiocyanate （NCS） radical and a BrC1 molecule was analyzed by quantum theory of atoms in molecules （QTAIM） and electron-localization function （EL...The nature of halogen bonding in five complexes formed between the thiocyanate （NCS） radical and a BrC1 molecule was analyzed by quantum theory of atoms in molecules （QTAIM） and electron-localization function （ELF） in this paper. The calculated results show that the geometry of the halogen atom bonded at the N-atom is stable than those bonded at S- or C-atom. The molecular electrostatic potentials determine the geometries and stabilities of the complexes. The valence basin of the S- or N-atom in the electron-donating NCS radical is compressed and its population decreases during the process of formation of the halogen-bonded complexes.展开更多
基金Project supported by the Shanghai Development Foundation from Science and Technology, China （Grant Nos 06JC14082 and 06QA14062）, the National Natural Science Foundation of China （Grant No 10535010）, and the Knowledge Innovation Project of Chinese Academy of Sciences （Grant No KJXC3-SYW-N2）.
文摘We investigate the differential cross sections （DCS） of elastic electron scattering from CH4, CF4 and SF6 at six impact energies in a range of 100 700eV by employing the independent atom model （IAM） together with the relativistic partial waves. The atom is present in an optical potential which is complex, spherically symmetric, and energy dependent. The optical potential of the atom is the sum of the direct static, dynamic polarization, local exchange and modified absorption potentials. The results obtained by using a modified absorption potential show significant improvements on the unmodified absorption potential results. The present results are generally in good agreement with experimental data available. In addition, the present results indicate that the structure of molecule manifests the observable effects on electron- molecule scattering.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 20073018).
文摘The potential acting on an electron within a molecule (PAEM) is formulated, and then calculated using the ab initio MELD program plus a separate calculation program in the RHF molecular orbital theory, finally the three-dimensional graphs of the potentials have been drawn. We have systematically investigated this kind of the potentials for a series of the diatomic molecules, such as HF, HCl, HBr, LiF, LiCl, and so on. The three-dimensional graph can clearly display the variation of the potential felt by an electron within a molecule and get a deeper understanding of the electronic motion and chemical bonding within a molecule.
基金Supported by the National Natural Science Foundation of China（Nos.21473083, 21133005）.
文摘A new approach to calculate the potential acting on an electron in a molecule（PAEM） has been established for drawing the molecular face（MF） of a macromolecule, according to the classic point charge model and the atom-bond electronegativity equalization method（ABEEMσπ） for one electron in a molecule. We introduced a dy- namic charge distribution from the view of a local electron movement in a molecule based on the new approach, and as further direct evidence, we calculated some physical quantities using the original ab initio method and the new method to verify the accuracy of the method, such as the boundary distance（BD）, molecular face surface area（MFSA） and molecular reactivities indicated by the MFs for a variety of organic molecules. All the results by the new method are in agreement with the results by ab initio method.
基金the National Natural Science Foundation of China(Grant No.20073018).
文摘The molecular intrinsic characteristic contour (MICC) is defined based on the clas-sical turning point of electron movement in a molecule. Three typical organic molecules, i.e. methane, methanol and formic acid, were employed as examples for detailed introduction of our method. Investigations on the cross-sections of MICC provide important information about atomic size changing in the process of forming molecules. The electron density distributions on the MICCs of these molecules were calculated and shown for the first time. Results showed that the electron density distribution on the MICC correlates closely with molecular chemical properties, and it provides a new insight into molecular boundary.
文摘By utilizing the classical turning point of the electron movement, we have defined and computed the mo-lecular intrinsic characteristic contour (MICC) via the com-bination of the ab initio quantum chemistry computational method with the ionization potential measured by photo-electron spectroscopy experiment. In this paper, we calcu-lated the MICCs of several small organic molecules contain-ing oxygen atom for the first time. The three-dimensional pictures have been drawn, by performing a large number of calculations. The analysis on some characterized cross-sec-tions of the MICC can provide atomic spatial changing information in the process of forming a molecule.
文摘The potential felt by a single electron within a molecule represents the total interaction energy of this electron with all nuclei and the rest electrons in the molecule and is an important quantity. It is formulated and then calculated by using the ab initio MELD program plus a separate calculation program. We have systematically investigated and discussed this kind of potentials for a series of molecules. In terms of the three dimensional graph, the variation of the potential acting on the single electron within a molecule has clearly and visually been shown, and hence the electronic movement and the chemical bonding can be deeply understood.
基金Project supported by the National Natural Science Foundation of China （Nos. 20973053, 20801017）, the Natural Science Foundation of Hebei Province （Nos. B 2011205058, B2010000371）, the Education Department Foundation of Hebei Province （Nos. 2009137, ZD2010126 ）.
文摘The nature of halogen bonding in five complexes formed between the thiocyanate （NCS） radical and a BrC1 molecule was analyzed by quantum theory of atoms in molecules （QTAIM） and electron-localization function （ELF） in this paper. The calculated results show that the geometry of the halogen atom bonded at the N-atom is stable than those bonded at S- or C-atom. The molecular electrostatic potentials determine the geometries and stabilities of the complexes. The valence basin of the S- or N-atom in the electron-donating NCS radical is compressed and its population decreases during the process of formation of the halogen-bonded complexes.
