Lithium silicates, such as $Li_2SiO_3$ and $Li_4SiO_4$, are considered as favorable candidates for the tritium breeding materials of a nuclear fusion reactor. Their bulk electronic properties and mechanics are important for the tritium behavior and tritium breeding blanket designs. We have studied the structural and electronic properties of $Li_2SiO_3$ and $Li_4SiO_4$ bulks using density functional theory (DFT) within generalized gradient approximation (GGA). The calculated crystal parameters are well consistent with the experimental results. The electronic band energy calculations show that $Li_2SiO_3$ and $Li_4SiO_4$ are insulators with a band gap of about 5.36 and 5.53 eV, respectively. Their valence band properties are mainly determined by the oxygen 2$p$ orbital electrons. The two types of oxygen atoms, nonbridging oxygen (NBO) atoms and bridging oxygen (BO) atoms, in $Li_2SiO_3$ reveal significantly different electron distribution of oxygen 2$p$ orbital. The Si 3$s$ and 3$p$ hybridization is observed in $Li_2SiO_3$, but not in $Li_4SiO_4$. In both lithium silicates, the electronic density increases more steeply around $Li$ and $Si$ atom sites compared with that around $O$ atoms. Additionally, the mechanical properties of both lithium silicates were calculated and discussed first time.

5-fluoro-1-(tetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione also known as tegafur, is an important component of Tegafur-uracil (UFUR), a chemotherapy drug used in the treatment of cancer. The equilibrium geometries of "Tegafur" and 5-fluoro-uracil (5-FU) have been determined and analyzed at DFT level employing the basis set 6-311+G(d, p). The molecular electrostatic potential surface which displays the activity centres of a molecule,  has been used along with frontier orbital energy gap, electric moments, first static hyperpolarizability,  to interpret the better selectivity of prodrug tegafur over the drug 5-FU. The harmonic frequencies of prodrug tegafur have also been calculated to understand its complete vibrational dynamics. In general, a good agreement between experimental and calculated normal modes of vibrations has been observed.

Multiphoton ionization of the $Na_2$ molecule by a single phase shaped femtosecond laser pulse has been theoretically studied using time-dependent quantum wave packet method including the effect of molecular rotation. We analyze the temporal development of the population and further discuss the molecular motion by mapping the rovibrational wave packet propagation in the excited state. The calculated results show a strong dependence of the kinetic energy-resolved photoelectron spectra on the laser chirp directions and the pulse duration.

The singly $(1s,ns)^{3}S^{e}$, $(1s,np)^{3}P^{o}$, $(1s,nd)^{3}D^{e}$ excited states and the doubly $_{2}(1,0)_{n}^{+1}S^{e}$ and $_{2}(1,0)_{n}^{-3}S^{e}$ $(n\leq10)$ autoionizing states of the helium isoelectronic sequence are investigated using Modified Atomic Orbital Theory (MAOT). Total energies up to $Z = 10$ and excitation energies with $Z = 2$~$5$ are presented and comparison with experimental and theoretical available results indicates a good agreement. In addition, the method is applied in the calculation of accurate results in very high $Z$ - He isoelectronic sequence with $11\leq Z\leq58$ and with $Z = 60,$ 70, 80, 90 and 92 for the $(1s,ns)^{1,3}S^{e}$, $(1s,np)^{1,3}P^{o}$, $(1s,nd)^{1,3}D^{e}$, $_{2}(1,0)_{n}^{+1}S^{e}$ and $_{2}(1,0)_{n}^{-3}S^{e}$ $(n\leq7)$ excited states. The results obtained for these high $Z$ - He isoelectronic sequence are in good agreement with double sums over the complete hydrogen spectrum calculations Ivanov and Safronova.

We investigate the thermodynamic properties of the potential superhard orthorhombic structure boron-carbonitride $\beta-BC_{2}N$ by using $ab$ $initio$ plane-wave pseudopotential density functional theory method within both local density approximation (LDA) and generalized gradient approximation (GGA). The lattice parameters ($a$, $b$ and $c$), equilibrium volume $V$, bulk modulus $B_{0}$ and its pressure derivative $B_{0}$' have been calculated, and compared with those of diamond and cubic boron nitride (c-BN). The obtained results are in excellent agreement with the available experimental data and other theoretical results. Through the quasi-harmonic Debye model, we also investigate the thermodynamic properties of $\beta-BC_{2}N.$ The variation of the thermal expansion $\alpha$, the heat capacity $C_{V}$ and the Grüneisen parameter $\gamma$ with pressure $P$ and temperature $T$, as well as the pressure-normalized volume ($P$-$V_{n}$) and the pressure- bulk modulus ($P$-$B$) relationship of $\beta-BC_{2}N$ are obtained systematically.

An embedded atom method potential for Ni-Al alloys is developed. The expression of the embedded function is constructed by analogy with the density function theory. Both the repulsive function and the electron density function here have simple forms. The potential parameters of pure Al and Ni are fitted to the experimental values, including their lattice parameters, cohesive energies, vacancy formation energies and three elastic constants $(c_{11}, c_{12}, c_{13})$. The potential for the Ni-Al alloy are then constructed from the Ni and Al potentials. The equation of states and the phonon dispersion calculated by the present potential parameters are in good agreements with first-principles calculations and experimental data, indicating the reliability of the present potential.

The Fisher information of Gaussian pure states is studied in this work. Based on the definition of joint non-classical properties, we calculate the non-classical properties of Gaussian pure states. The results show that the Fisher information and Fisher length are efficacious tools to study the non-classical properties of quantum states. And the non-classical properties of states can be used to calculate the quantum properties quantificationally. Making use of Fisher information, one can obtain the correlation between the Fisher information and quantum squeezing properties of Gaussian pure states. Especially, it is significative that one can quantificationally describe the fluctuation of quantum states by an alternative new method.

We have studied the model for interaction of two trapped ions in a trap with a laser beam in the intermediate excitation regime. By applying unitary transformations, the system can be transformed into the Tavis-Cummings model. The entanglement dynamics of two trapped ions in this system has been investigated. With computation of the concurrence, unlike that in Tavis-Cummings model, we find that the entanglement of two ions in our model undergoes periodic death and revivals.