Fig. 1: Crystal structures.

a Crystal structure of Eu₂ZnSb₂. The golden, green, and red spheres represent the europium, antimony, and zinc, respectively. b Zig-zag-type crystal structure of Eu₂ZnSb₂. c Crystal structure of EuAgSb. d Anionic AgSb layer in EuAgSb. See also Supplementary Material, Fig. S2.