We have studied the structure and optical properties of bimetallic (CuAg)_n (n = 1–6) nanoalloy clusters by using density functional theory (DFT) method. The computed data shows that HOMO-LUMO energy gaps of the clusters are in the range of 1.444–3.066 eV. The most stable cluster (CuAg)₃ with symmetry group C₁ and singlet spin multiplicity has an energy gap 3.066 eV, whereas the cluster (CuAg)₆ with symmetry group C₂ and singlet spin multiplicity shows the least energy gap (1.444 eV). Our study reveals an interesting correlation between energy gap, optical electronegativity, and refractive index. Computed data exhibits that clusters, in which Ag atoms are placed on the edge position and have less number of Ag–Ag bonds, display a large frequency range and the maximum intensity of IR and Raman spectra.

我们 使用密度泛函理论（DFT）方法研究了双金属（CuAg）_n（n = 1–6）纳米合金簇的结构和光学性质。计算数据表明，簇的HOMO-LUMO能隙在1.444–3.066 eV的范围内。具有对称组C ₁和单重态自旋多重性的最稳定簇（CuAg）₃的能隙为3.066 eV，而具有对称组C ₂的簇（CuAg）₆的能隙为3.066 eV。单重态自旋多重性显示出最小的能隙（1.444 eV）。我们的研究揭示了能隙，光学电负性和折射率之间的有趣关系。计算数据表明，其中银原子位于边缘位置且具有较少的Ag-Ag键数目的簇显示较大的频率范围，并具有IR和拉曼光谱的最大强度。