Determination of the crystallographic and electronic structure of U ₂Fe ₃Si ₅ compound

The crystallographic structure of ternary U ₂Fe ₃Si ₅ compound described by C2/c space group was determined on the basis of X-ray powder diffraction data. The lattice parameters a = 10.8483(3) , b = 11.4802(4) , c = 5.5178(2) and β = 119.428(1)) and the atomic coordinates were refined by Rietveld method with the reliability factors R _p = 7.3%, R _wp = 9.4%. Optimization of the proposed atomic model was performed on the basis of Density Functional Theory (DFT) calculations. Close crystallographic relationship exists between the structures of monoclinic U ₂Fe ₃Si ₅ compound and the orthorhombic U ₂Co ₃Si ₅ phase; the atomic model of the U ₂Fe ₃Si ₅ compound can be deduced theoretically as a subgroup C2/c of the group Ibam describing the structure of the U ₂Co ₃Si ₅ silicide.