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We report the structural, electronical, and heavy nuclear 205 Tl Nuclear Magnetic Resonance (NMR) shielding properties of thallium halides TlX (X = F, Cl, Br, and I) by the first principles calculation. The Perdew-Burke-Ernzerhof Generalized Gradient Approximation, Yukawa Screened-PBE0 hybrid functional, and modified Becke-Johnson (mBJ) functionals including the relativistic and spin-orbit coupling effects are applied for calculation of the exchange-correlation potentials. Calculated PDOS spectra display that the valence band is composed of the X-s, Tl-5d, X-p, and Tl-6s states, and these states play an important role in 205 Tl NMR shielding. Our findings indicate that the nuclear magnetic shielding parameters depend on the electronic properties.Obtained results by mBJ show that there is a close agreement between the experimental and the calculated NMR parameters.

Several methods are introduced for skin cancer treatment. An encouraging method is radionuclide skin therapy, where high-energy beta emitting radionuclides such as P,Y, Re andHo are employed for skin irradiation. This study aimed to calculate the dose distribution for mentioned radionuclides at different layers of skin phantom through Monte Carlo simulation. Depth dose distribution, transverse dose profile and isodose curves related to the patch sources under investigation were calculated by MCNPX code. All of calculations were performed inside a developed skin phantom. Obtained results were compared with those reported by other studies to evaluate the validity of simulations. The results showed that the Ho andP have steeper dose gradient within the depth which can lead to the better normal tissue sparing. Simulated depth dose distributions were in a good agreement with other published studies and confirmed the validity of performed simulations. The obtained transverse dose profiles at 0.2 mm depth had acceptable symmetry and flatness that can improve the dose uniformity within the target area. Calculated isodose curves showed that the 90% isodose level covers a circular area with the diameter of around 8 mm for all studied beta sources. From the results, it can be concluded that Ho andP are more effective in treatment of superficial skin lesions, while, Y andRe are more rational choices in treatment of deeply distributed skin tumors. Size of employed patch source should be based on the target area to minimize the delivered dose to the adjacent tissues.