We report on the calculations of transition wavelengths and weighted oscillator strengths for 2s22p^6 2s2p^6np （4 〈 n 〈 20） electric dipole （El） transitions of Cu^19＋ ion. The flexible atomic code （FAC） has been adopted for the calculations. Comparisons are made with the experimental data available, showing that the present results for 4 〈 n 〈 6 are more accurate than the previous calculated values. Furthermore, combining the quantum defect theory （QDT） with the transition energies of 2s^22p^62s2p^6np, the quantum defects for 2s2p^6np Rydberg series of Cu^19＋ ion are determined. In addition, the energies of any highly excited states （n 〉 20） for this series can be reliably predicted using the QDT and the given quantum defects. The ionization energies for Cu^19＋ and Cu^20＋ ions are also calculated and they excellently accord with previous experimental and calculated values.
By using first-principles simulations based on time-dependent density functional theory,the chemical reaction of an HCl molecule encapsulated in C60induced by femtosecond laser pulses is observed.The H atom starts to leave the Cl atom and is reflected by the C60wall.The coherent nuclear dynamic behaviors of bond breakage and recombination of the HCl molecule occurring in both polarized parallel and perpendicular to the H–Cl bond axis are investigated.The radial oscillation is also found in the two polarization directions of the laser pulse.The relaxation time of the H–Cl bond lengths in transverse polarization is slow in comparison with that in longitudinal polarization.Those results are important for studying the dynamics of the chemical bond at an atomic level.
A new hydrogen storage route of 3D nanoporous sodium borohydride (NPSB) generated by removing special atoms is proposed in this work. Three different size pores of NPSB-1 (7), NPSB-2 (10) and NPSB-3 (14) are presented, and the hydrogen storage capacities of these NPSBs are simulated by employing a grand canonical Monte Carlo (GCMC) procedure for a temperature range of 77-298 K and a pressure range of 0.1-100 bar. The effects of pore diameter, temperature and pressure on the hydrogen adsorption have been examined. The results show that the adsorption of hydrogen decreases and increases with increasing temperature and hydrogen pressure, respectively. It also reflects that the hydrogen adsorption capacities at higher pressures are dependent on pore diameter, while independent of pore diameter at lower pressures.
We report theoretical studies on the plasmon resonances in linear Au atomic chains by using ab initio time- dependent density functional theory. The dipole responses are investigated each as a function of chain length. They converge into a single resonance in the longitudinal mode but split into two transverse modes. As the chain length increases, the longitudinal plasmon mode is redshifted in energy while the transverse modes shift in the opposite direction （blueshifts）. In addition, the energy gap between the two transverse modes reduces with chain length increasing. We find that there are unique characteristics, different from those of other metallic chains. These characteristics are crucial to atomic-scale engineering of single-molecule sensing, optical spectroscopy, and so on.
The binding energies, geometric structures and electronic properties of molybde- num trioxide （MOO3） molecule encapsulated inside （8, 0）, （9, 0）, （10, 0） and （14, 0） single-walled carbon nanotubes （SWNTs） have been investigated using density functional theory （DFT） method. Due to curvature effect, the calculated binding energy values are different, the variation of which indicated that the stability of MoO3/SWNT systems increases with increasing the radius of SWNTs. At the same time, owing to the presence of MoO3 molecule, the band gap of MoO3/SWNTs systems decreases. The analysis of density of states （DOS） reveals hybridization between C-2p and Mo-4d and between C-2p and O-2p orbitals near the Fermi level, which results in electron transfer from SWNTs to MoO3 molecule. The present computations suggest that electronic properties of SWNTs can be modified by doping MoO3 molecule.
We studied the co-adsorption of hydrogen molecule and ions （Li, K, Mg, Ca） inside the single-walled carbon nanotubes （SWNTs） by using density-functional theory （DFT）. The band structures （BS）, density of states （DOS）, charge transfer and difference charge density are presented. We discussed the interaction between the ions （Li, K, Mg, Ca） and H2 Meanwhile, the binding energy indicates that ionization can increase the adsorption energy of H2 in CNT.
