---

At the present work the ab-initio calculations based on pseudo-potential plane wave method were performed to study the structural, electronic, phononic and thermodynamic properties of GaBi compound in the stable Zinc-Blende phase. In order to investigate the role of spin-orbit interactions, in our calculations the relativistic effects have been regarded as well. Ground state parameters are computed and compared with available theoretical and experimental works. Results revealed that GaBi is a semi-metal material. Relativistic calculations suggest that GaBi has a negative band gap and these calculations to study the thermal properties of this compound is not necessary.

---

 "Algebraic cluster model" (ACM) is used to describe the relative motion of the cluster by considering vibrational and rotational degrees of freedom.In this research, using the two-body ACM Hamiltonian, the quantum phase transition in the transition region U(3)↔O(4) for odd nuclear structures such as: ⁸Be،⁹B، ⁹Be, and ¹⁰B has been investigated. The energy surfaces, the expectation value of the boson number operator as a function of the control parameters of the calculated Hamiltonian, and also the effect of pairing the odd nucleon with the even-even boson nucleus at the critical point are discussed.   Experimental data confirm the numerical results.
 

---

Based on the density functional theory and the GGA approximation, by applying the improved potential of TB-mbJ the structural, electronic, optical, and thermodynamic properties of the XVSi semiconductor compounds (X = Co, Rh) and its [001] films Were studied. These two heusler compounds with the non-magnetic semiconductor behavior are stable in the MgAgAs-type cubic structure with F4-3m space group. Due to the good responses of the real and imaginary parts of the dielectric function for CoVSi and RhVSi in the visible spectrum range and the low electronic loss function, these two heuslers will be suitable for optical applications in this energy range. An examination of the stability phase diagram of [001] films showed that all 6 of its possible terminations would be thermodynamically stable. The electronic structure of these films indicates the emergence of half-metallic magnetic behavior only for two terms of V-Si: CoVSi [001] and   V-Si: RhVSi[001]. The responses of the dielectric function, as well as the absorption spectra of the two terms, are similar to those of the Bulk state, but with less intensity, while the electron loss in these two films is greater than that of the Bulk.