Extraction of the complete quantum mechanics from X‐ray scattering data is the ultimate goal of quantum crystallography. This article delivers a perspective for that possibility. It is desirable to have a method for the conversion of X‐ray diffraction data into an electron density that reflects the antisymmetry of an N‐electron wave function. A formalism for this was developed early on for the determination of a constrained idempotent one‐body density matrix. The formalism ensures pure‐state N‐representability in the single determinant sense. Applications to crystals show that quantum mechanical density matrices of large molecules can be extracted from X‐ray scattering data by implementing a fragmentation method termed the kernel energy method (KEM). It is shown how KEM can be used within the context of quantum crystallography to derive quantum mechanical properties of biological molecules (with low data‐to‐parameters ratio). © 2017 Wiley Periodicals, Inc.

中文翻译：

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量子晶体学：一个观点

从 X 射线散射数据中提取完整的量子力学是量子晶体学的最终目标。本文为这种可能性提供了一个视角。希望有一种方法可以将 X 射线衍射数据转换为反映 N 电子波函数反对称性的电子密度。早期为此开发了一种形式主义，用于确定受约束的幂等单体密度矩阵。形式主义确保了单行列式意义上的纯状态 N 可表示性。对晶体的应用表明，可以通过实施称为核能法 (KEM) 的碎裂方法从 X 射线散射数据中提取大分子的量子力学密度矩阵。展示了如何在量子晶体学的背景下使用 KEM 来推导出生物分子的量子力学特性（具有低数据参数比）。© 2017 威利期刊公司。