First-Principles Calculations of x-Dependent Ground Structures and Optical Properties of Ca(x)La(1–x)B(6)

[Image: see text] High transparency in the visible region is desired to manufacture solar control films and glasses for various applications. To improve the visible light transparency of LaB(6) nanoparticles which exhibit strong absorption in the near-infrared region, the substitution of La with Ca is investigated using first-principles calculations. Among the numerous atomic replacement configurations in Ca(x)La(1–x)B(6), all 762 structures existing in the supercells that are up to 8 times the primitive cell are comprehensively evaluated, and the most stable ground structures in Ca(x)La(1–x)B(6) are deduced. The optical properties of the ground structures are derived by performing high-precision calculations using the HSE06 functional, which reveal that Ca(x)La(1–x)B(6) with 0 < x < 1/4 is preferred as a solar shielding material with improved visible transparency. This method is effective for the investigation of the effect of substitutional elements in composite compounds on their physical properties.