Lattice and magnetism in superconducting compounds Ca_1-xK_xFe₂As₂

Based on the density functional theory (DFT), using the scheme of the linearized augmented plane wave and the improved local orbital (APW + lo), the structure, the electronic bands and the magnetism of superconducting compounds Ca_1-xK_xFe₂As₂ (x = 0, 0.25, 0.5, 0.75, 1) are optimized and calculated. The calculation results indicate that with K-doping the lengths of the a, b axes can decrease, and the length of the c axis, the volume, the energy of spin-down valence bands, and the DOS at the Fermi level can increase, which leads the magnetic moment of the system to increase.