Linear, planar, and tubular molecular structures constructed by double planar tetracoordinate carbon D2h C2(BeH)4 species via hydrogen-bridged -BeH2Be- bonds. - Xue-Feng Zhao; Haixia Li; Caixia Yuan; Yan-Qin Li; Yan-Bo Wu; Zhi-Xiang Wang (J. Comput. Chem., 2016)