Compton spectroscopy measurements on tantalum dichalcogenide TaS_0.5Se_1.5 using a 100 mCi Am-241 γ-ray Compton spectrometer are presented. Experimental Compton profile (CP) is compared with those computed using linear combination of atomic orbitals (LCAO) method within the density functional theory (DFT) and hybrid functionals of Hartree-Fock and DFT. Hybrid functional namely WC1LYP based CP is found in better accordance with the experimental CP. The relative nature of bonding in TaS_0.5Se_1.5 and TaSSe is interpreted by scaling the experimental CP on equal-valence-electron-density and Mulliken's population analysis. Origin of metallic behaviour of TaS_0.5Se_1.5 is discussed in terms of energy bands and density of states. It is seen that the 5d states of Ta dominate around the Fermi level leading to metallic character of the compound. Fermi surface topology and optical response like dielectric constants, absorption coefficients, etc. of TaS_0.5Se_1.5 are also described using modified Becke-Johnson theory of full-potential linearized augmented plane wave approach.

介绍了使用100 mCi Am- 241γ射线康普顿光谱仪对二硫化钽TaS _0.5 Se _1.5进行康普顿光谱测量的方法。将实验康普顿轮廓（CP）与在密度泛函理论（DFT）以及Hartree-Fock和DFT的混合泛函中使用原子轨道（LCAO）方法的线性组合进行线性计算的结果进行了比较。发现混合功能，即基于WC1LYP的CP更好地符合了实验CP。TaS _0.5 Se _1.5和TaSSe中键的相对性质可以通过等价电子密度和Mulliken种群分析的比例缩放实验CP来解释。TaS _0.5 Se _1.5的金属行为起源根据能带和状态密度来讨论。可以看出，Ta的5d态在费米能级附近占主导地位，导致该化合物具有金属特性。TaS _0.5 Se _1.5的费米表面拓扑和光学响应，如介电常数，吸收系数等，也使用改良的Becke-Johnson全势线性化增强平面波方法进行了描述。