We calculate structural, electronic properties and chemical bonding of borate Li4CaB2O6 under high pressure by means of the local density-functional pseudopotential approach. The equilibrium lattice constants, density...We calculate structural, electronic properties and chemical bonding of borate Li4CaB2O6 under high pressure by means of the local density-functional pseudopotential approach. The equilibrium lattice constants, density of states, Mulliken population, bond lengths, bond angles as well as the pressure dependence of the band gap are presented. Analysis of the simulated high pressure band structure suggests that borate Li4CaB2O6 can be used as the semi-conductor optical material. Based on the Mulliken population analysis, it is found that the electron transfer of the Li atom is very different from that of other atoms in the studied range of high pressures. The charge populations of the Li atom decrease with the pressure up to 60 GPa, then increase with the pressure.展开更多
Density function theory calculations of frequency-dependent optical rotations [α]ω for three rigid chiral molecules are reported. Calculations have been carried out at the sodium D line frequency, using the ADZP bas...Density function theory calculations of frequency-dependent optical rotations [α]ω for three rigid chiral molecules are reported. Calculations have been carried out at the sodium D line frequency, using the ADZP basis set and a wide variety of functionals. Gauge-invariant atomic orbitals are used to guarantee origin-independent values of [ω]D. In addition, study of geometry dependence of [ω]D is reported. Using the geometries optimized at the B3LYP/ADZP level, the mean absolute deviation of B3LYP/ADZP and experimental laiD values yields 60.1°/（dm g/cm^3）. According to our knowledge, this value has not been achieved until now with any other model.展开更多
A new type of bismuth silicate glass （Bi2O3-SiO2-ZnO-Al2O3-La2O3） doped with Tm2O3 is prepared by melt-quenching method. The thermal stability of the glass is examined by differential scanning calorimetry. No crysta...A new type of bismuth silicate glass （Bi2O3-SiO2-ZnO-Al2O3-La2O3） doped with Tm2O3 is prepared by melt-quenching method. The thermal stability of the glass is examined by differential scanning calorimetry. No crystallization peak is found. Using the absorption and emission spectra, the absorption and emission cross-sections are calculated. Their maximum data are 2.9×10^-21cm^2 at 1663 nm and 4.7×10^-21cm^2 at 1826 nm, respectively. Using the Judd-Ofelt theory, the radiation transition probabilities and radiative lifetimes are obtained. The extended overlap integral method is applied to analyze energy transfer process among the Tm3＋ ions. The transfer constants of cross-relaxation and energy migration among the Tm^3＋ ions at the 3H4 level are 7.60×10^-40 and 14.98×10^-40 cm^6 /s, respectively. The critical transfer radius for cross-relaxation is 0.99 nm. The cross relaxation process is easy to realize and is favorable for obtaining ～2-μm laser.展开更多
We have carried out calculations to search Borromean windows(BWs) for 11 different three-body systems interacting with screened Coulomb(Yukawa-type) potentials using Hylleraas-type wave functions within the framework ...We have carried out calculations to search Borromean windows(BWs) for 11 different three-body systems interacting with screened Coulomb(Yukawa-type) potentials using Hylleraas-type wave functions within the framework of a variational approach. The critical values of the screening parameters for the ground states of the systems under consideration are reported for which the three-body systems are stable, while all the possible fragments are unbound;that is, it shows windows for Borromean binding.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10676025.
文摘We calculate structural, electronic properties and chemical bonding of borate Li4CaB2O6 under high pressure by means of the local density-functional pseudopotential approach. The equilibrium lattice constants, density of states, Mulliken population, bond lengths, bond angles as well as the pressure dependence of the band gap are presented. Analysis of the simulated high pressure band structure suggests that borate Li4CaB2O6 can be used as the semi-conductor optical material. Based on the Mulliken population analysis, it is found that the electron transfer of the Li atom is very different from that of other atoms in the studied range of high pressures. The charge populations of the Li atom decrease with the pressure up to 60 GPa, then increase with the pressure.
文摘Density function theory calculations of frequency-dependent optical rotations [α]ω for three rigid chiral molecules are reported. Calculations have been carried out at the sodium D line frequency, using the ADZP basis set and a wide variety of functionals. Gauge-invariant atomic orbitals are used to guarantee origin-independent values of [ω]D. In addition, study of geometry dependence of [ω]D is reported. Using the geometries optimized at the B3LYP/ADZP level, the mean absolute deviation of B3LYP/ADZP and experimental laiD values yields 60.1°/（dm g/cm^3）. According to our knowledge, this value has not been achieved until now with any other model.
基金supported by the National Natural Science Foundation of China (No. 60937003)GFfoundation (No. GXJJ-11-M23).
文摘A new type of bismuth silicate glass （Bi2O3-SiO2-ZnO-Al2O3-La2O3） doped with Tm2O3 is prepared by melt-quenching method. The thermal stability of the glass is examined by differential scanning calorimetry. No crystallization peak is found. Using the absorption and emission spectra, the absorption and emission cross-sections are calculated. Their maximum data are 2.9×10^-21cm^2 at 1663 nm and 4.7×10^-21cm^2 at 1826 nm, respectively. Using the Judd-Ofelt theory, the radiation transition probabilities and radiative lifetimes are obtained. The extended overlap integral method is applied to analyze energy transfer process among the Tm3＋ ions. The transfer constants of cross-relaxation and energy migration among the Tm^3＋ ions at the 3H4 level are 7.60×10^-40 and 14.98×10^-40 cm^6 /s, respectively. The critical transfer radius for cross-relaxation is 0.99 nm. The cross relaxation process is easy to realize and is favorable for obtaining ～2-μm laser.
基金Supported by the National Natural Science Foundation of China under Grant No.11304086the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province of China under Grant No.UNPYSCT-2015019the Natural Science Foundation for Distinguished Young Scholars in Heilongjiang University under Grant No.JCL201503
文摘We have carried out calculations to search Borromean windows(BWs) for 11 different three-body systems interacting with screened Coulomb(Yukawa-type) potentials using Hylleraas-type wave functions within the framework of a variational approach. The critical values of the screening parameters for the ground states of the systems under consideration are reported for which the three-body systems are stable, while all the possible fragments are unbound;that is, it shows windows for Borromean binding.
