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The plane-wave pseudopotential method using the generalized gradient approximation within the density functional theory is used to investigate the structure and bulk modulus of WSi2. The quasi-harmonic Debye model, using a set of total energy versus cell volume obtained with the plane-wave pseudopotential method, is applied to the study of the elastic properties and vibrational efiects. We have analysed the bulk modulus of WSi2 up to 1600 K. The major trend shows that the WSi2 crystal becomes more compressible when the temperature rises and the increase of compressibility leads to the decrease of Debye temperature. The predicted temperature and pressure efiects on the thermal expansion, heat capacity and Debye temperatures are determined from the non-equilibrium Gibbs functions and compared with the data available.

A general cascade package is used to handle the J/ψ and ψ' production and absorption for different ET bins in S-U and Pb-Pb collisions. We study the combined effect of nuclear absorption and final state interaction with co-movers on the J/ψ and ψ' suppression. The experimental data of J/ψ production can be fitted for different ET-bins in S-U collisions and for lower ET-bins in Pb-Pb collisions. However, ψ' data for high ET-bins in both S-U and Pb-Pb collisions can not be explained.

When the cross section of J/ψ production is considered as varying with the energy of the nucleon-nucleon interaction, the production of J/ψ in pA and AA collisions has been studied by using FRITIOF Model. The calculation shows that the cross section of J/ψ production "per nucleon-nucleon collision" decreases with the increasing mass number and centrality as a consequence of continuous energy loss of the projectile nucleons to the target nucleons in their successive binary nucleon-nucleon collisions. The model predictions have been compared with the experimental data of J/ψ production.

This paper applies the density functional theory method to optimise the structure for X3Δ state of TiO molecule with the basis sets 6–31G, 6–31++G and 6–311G**. Comparing the attained results with the experiments, it obtains the conclusion that the basis set 6–31++G is most suitable for the optimal structure calculations of X3 Δ state of TiO molecule. The whole potential energy curve for the electronic state is further scanned by using B3P86/6–31++G method for the ground state, then it uses a least square fitted to Murrell–Sorbie functions, at last it calculates the spectroscopic constants and force constants, which are in better agreement with the experimental data.

The plane-wave pseudopotential method using the generalized gradient approximation within the framework of density functional theory is applied to anaylse the bulk modulus, thermal expansion coefficient and heat capacity of LaB6. The quasi-harmonic Debye model, using a set of total energy versus volume obtained with the plane-wave pseudopotential method, is applied to the study of the thermal properties and vibrational effects. We analyse the bulk modulus of LaB6 up to 1500 K. The elastic properties calculations show that our system is mechanically stable. For the heat capacity and the thermal expansion, significant differences in properties are observed above 300K. The calculated zero pressure bulk modulus is in good agreement with the experimental data. Moreover, the Debye temperatures are determined from the non-equilibrium Gibbs functions and compared to available data.

The plane-wave pseudopotential method using the generalized gradient approximation within the framework of density functional theory is applied to analyse the lattice parameters, elastic constants, bulk moduli, shear moduli and Young's moduli of WSi2. The quasi-harmonic Debye model, using a set of total energy versus cell volume obtained with the plane-wave pseudopotential method, is applied to the study of the elastic properties and vibrational effects. The athermal elastic constants of WSi2 are calculated as a function of pressure up to 35 GPa. The relationship between bulk modulus and temperature up to 1200 K is also obtained. Moreover, the Debye temperature is determined from the non-equilibrium Gibbs function. The calculated results are in good agreement with the experimental data.