title: Trigonal Planar [HgSe3](4-) Unit: A New Kind of Basic Functional Group in IR Nonlinear Optical Materials with Large Susceptibility and Physicochemical Stability.
abstract: A new mercury selenide BaHgSe2 was synthesized. This air-stable compound displays a large nonlinear optical (NLO) response and melts congruently. The structure contains chains of corner-sharing [HgSe3](4-) anions in the form of trigonal planar units, which may serve as a new kind of basic functional group in IR NLO materials to confer large NLO susceptibilities and physicochemical stability. Such trigonal planar units may inspire a path to finding new classes of IR NLO materials of practical utility that are totally different from traditional chalcopyrite materials.
authors.affiliation: Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, P.R. China.|University of Chinese Academy of Sciences , Beijing 100049, P.R. China.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Chemistry, University of Alberta , Edmonton, Alberta, Canada T6G 2G2.|Institute of Chemical Materials, China Academy of Engineering Physics , Mianyang 621900 P.R. China.
authors.forename: Wenlong
authors.initials: W
authors.lastname: Yin
authors.affiliation: Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, P.R. China.|University of Chinese Academy of Sciences , Beijing 100049, P.R. China.
authors.forename: Pifu
authors.initials: P
authors.lastname: Gong
authors.affiliation: Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, P.R. China.|University of Chinese Academy of Sciences , Beijing 100049, P.R. China.
authors.forename: Xiaoshuang
authors.initials: X
authors.lastname: Li
authors.affiliation: Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, P.R. China.|University of Chinese Academy of Sciences , Beijing 100049, P.R. China.
authors.forename: Molin
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, University of Alberta , Edmonton, Alberta, Canada T6G 2G2.
authors.forename: Arthur
authors.initials: A
authors.lastname: Mar
authors.affiliation: Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, P.R. China.
authors.forename: Zheshuai
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, P.R. China.
authors.forename: Jiyong
authors.initials: J
authors.lastname: Yao
authors.affiliation: Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, P.R. China.
authors.forename: Yicheng
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Beijing Center for Crystal Research and Development, Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, P.R. China.
authors.forename: Chuangtian
authors.initials: C
authors.lastname: Chen