AXHg3P2S8 (A = Rb, Cs; X = Cl, Br): New Excellent Infrared Nonlinear Optical Materials with Mixed‐Anion Chalcohalide Groups of Trigonal Planar [HgS2X]3− and Tetrahedral [HgS3X]5−. Issue 24 (18th December 2021) - Xing, Wenhao; Tang, Chunlan; Wang, Naizheng; Li, Chunxiao; Uykur, Ece; Wu, Jieyun; Lin, Zheshuai; Yao, Jiyong; Yin, Wenlong; Kang, Bin