The crystal structure of L-5-methyltetrahydrofolate calcium trihydrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Calcium levomefolate trihydrate crystallizes in space group P212121 (#19) with a = 7.1706(6), b = 6.5371(5), c = 53.8357(41) Å, V = 2523.58(26) Å3, and Z = 4. The structure is characterized by alternating hydrophobic and hydrophilic layers along the c-axis. The Ca cations are 7-coordinate, and share edges to form chains along the b-axis. Each of the water molecules acts as a donor in two hydrogen bonds. The coordinated water molecule makes two strong intermolecular O–H⋯O hydrogen bonds to carboxyl and carbonyl groups. The two zeolitic water molecules form weaker hydrogen bonds, to carbonyl O atoms, ring N atoms, and aromatic C atoms. Several N–H⋯O/N hydrogen bonds, as well as C–H⋯O hydrogen bonds, also contribute to the lattice energy.

中文翻译：

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L-5-甲基四氢叶酸钙三水合物 I 型晶体结构，C20H23N7O6Ca(H2O)3

使用同步加速器 X 射线粉末衍射数据解析和精炼了 L-5-甲基四氢叶酸钙三水合物的晶体结构，并使用密度泛函技术进行了优化。左甲叶酸钙三水合物在空间群中结晶磷212121(#19) 与A= 7.1706(6),乙= 6.5371(5),C= 53.8357(41) 埃,V= 2523.58(26) 埃3， 和Z= 4. 该结构的特点是疏水层和亲水层沿着C-轴。Ca 阳离子是 7 配位的，并且共享边缘以沿着乙-轴。每个水分子充当两个氢键的供体。配位的水分子与羧基和羰基形成两个强分子间 O-H⋯O 氢键。两个沸石水分子与羰基O原子、环N原子和芳香族C原子形成较弱的氢键。一些 N-H⋯O/N 氢键以及 C-H⋯O 氢键也对晶格能有贡献。