Ultrawide Bandgap and Record-High Birefringence in a Covalent Beryllium-Organic Framework - Peng-Hui Guo; Xia Zhang; Miriding Mutailipu; Sangen Zhao; Nan Zhang; Yao Guo; Lei Huai; Yi-Gang Chen; Xian-Ming Zhang (Journal of the American Chemical Society, 2026)