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.
The isothermal bulk modulus and its first pressure derivative of NaCl are investigated using the classical molecular dynamics method and the quasi-harmonic Debye model. To ensure faithful molecular dynamics simulations, two types of potentials, the shell-model （SM） potential and the two-body rigid-ion Born-Mayer-Huggins-FumiqTosi （BMHFT） potential, are fully tested. Compared with the SM potential based simulation, the molecular dynamics simulation with the BMHFT potential is very successful in reproducing accurately the measured bulk modulus of NaCl. Particular attention is paid to the prediction of the isothermal bulk modulus and its first pressure derivative using the reliable potential and to the comparison of the SM and the BMHFT potentials based molecular dynamics simulations with the quasi-harmonic Debye model. The properties of NaCl in the pressure range of 0-30 GPa at temperatures up to the melting temperature of 1050 K are investigated.
The thermodynamic and elastic properties of magnesium silicate （MgSiO3） perovskite at high pressure are investigated with the quasi-harmonic Debye model and the first-principles method based on the density functional theory. The obtained equation of state is consistent with the available experimental data. The heat capacity and the thermal expansion coefficient agree with the observed values and other calculations at high pressures and temperatures. The elastic constants are calculated using the finite strain method. A complete elastic tensor of MgSiO3 perovskite is determined in the wide pressure range. The geologically important quantities： Young＇s modulus, Poisson＇s ratio, Debye temperature, and crystal anisotropy, are derived from the calculated data.
