C₂H₁₂N₆C₄O₄·2H₂O and Na₂C₄O₄·3H₂O: Two Ultraviolet Birefringent Compounds with the [C₄O₄]²– Group

In modern optics, birefringent materials that can manipulate light polarization play important roles in lasers and information fields. The search for ultraviolet (UV) crystals with large birefringence is the focus of attention in the field of optical materials. In this work, we synthesized two birefringent crystals, C