The crystal structure of cefprozil monohydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Cefprozil monohydrate crystallizes in space group P21 (#4) with a = 11.26513(6), b = 11.34004(5), c = 14.72649(11) Å, β = 90.1250(4)°, V = 1881.262(15) Å3, and Z = 4. Although a reasonable fit was obtained using an orthorhombic model, closer examination showed that many peaks were split and/or had shoulders, and thus the true symmetry was monoclinic. DFT calculations revealed that one carboxylic acid proton moved to an amino group. The structure thus contains one ion pair and one pair of neutral molecules. This protonation was confirmed by infrared spectroscopy. There is an extensive array of hydrogen bonds resulting in a three-dimensional network. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.

中文翻译：

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(Z)-头孢丙烯一水合物的晶体结构，C18H19N3O5S(H2O)

头孢丙烯一水合物的晶体结构已使用同步加速器 X 射线粉末衍射数据进行求解和改进，并使用密度泛函技术进行了优化。头孢丙烯一水合物在空间群中结晶磷21(#4) 与一种= 11.26513(6),b= 11.34004(5),C= 14.72649(11) 埃，β= 90.1250(4)°,五= 1881.262(15) Å3， 和Z= 4. 虽然使用正交模型获得了合理的拟合，但仔细检查发现许多峰是分裂的和/或有肩峰，因此真正的对称性是单斜的。DFT 计算表明一个羧酸质子移动到一个氨基上。因此该结构包含一对离子对和一对中性分子。红外光谱证实了这种质子化。有大量的氢键形成一个三维网络。粉末图案已提交给ICDD®包含在粉末衍射文件™中。