National Crystallography Service 2006 Renewal

X射线结晶学是用来描述利用晶体样品的X射线衍射在原子水平上获得晶体内部结构的图像的术语。当组成原子或分子聚集成一个紧密排列的阵列时，晶体结构就形成了，该阵列在三维上具有重复的图案。X射线的波长与重复晶体结构图案中的间距具有相同的数量级，并被原子的电子云散射。原子散射和重复图案的组合产生了衍射，其中特定的衍射束在有限数量的明确定义的方向上发射。如果用X射线探测器记录这些衍射束的方向和强度，就有可能使用模拟光学显微镜行为的计算机程序来生成晶体结构中电子密度分布的图像，从而使我们能够识别固体中的分子结构。这项技术在20世纪初被首次引入，并经历了许多变化和改进。这项技术发展的基础是X射线产生能力的提高，衍射X射线探测技术的改进，以及用于处理衍射数据和计算晶体结构图像的计算机软件的改进。随着这些技术的发展，该技术的功率得到了极大的提高，但成本也有所提高。然而，在高强度的情况下，有可能缩短一次实验所需的时间，而在如此高产量的来源下，共享它们变得合乎逻辑，并支持许多已经产生晶体并需要确认或知道化合物结构的用户。因此，1981年为英国学术化学家创建了一个共享设施，从那时起，这一直作为国家服务运营。该服务的目的是识别、获取和操作最新的X射线衍射技术，并将其提供给其他机构的用户。2001年出现了一项重大进展，当时进入达累斯伯里同步站的单晶设施--9.8站--被纳入了服务业务。这提供了令人难以置信的高亮度X射线束，使研究仅有几微米大小的单晶成为可能，相当于粉末的单个颗粒。对于南安普顿的实验室源和同步加速器源的使用，通过使用仍在开发的软件，可以扩展联合军种提供的能力，该软件可以处理数据并解析质量非常差的晶体的结构/具有固有的生长缺陷或由于其柔软和杂乱的性质而造成的损坏。随着化学家合成更大、更复杂、蓬松的分子，成功处理这些类型的晶体是发展当前焦点材料化学以及了解其化学和物理性质的关键。国家晶体服务局还汇集了处理英国其他地方无法成功研究的疑难样品的特殊专业知识。

X-ray crystallography is the term used to describe the use of X-ray diffraction from a crystalline sample to obtain a picture of the internal structure of the crystal at the atomic level. Crystal structures are formed when the component atoms or molecules assemble into a closely packed array that has a repeating pattern in three dimensions. X-rays have a wavelength that is of the same order of magnitude as the spacings in the repeating crystal structure pattern, and are scattered by the electron cloud of the atoms. The combination of the atomic scattering and the repeating pattern produces diffraction, in which specific diffracted beams are emitted in a finite number of well-defined directions. If the directions and intensities of these diffracted beams are recorded, using an X-ray detector, it is possible to use a computer program that simulates the actions of an optical microscope to generate an image of the electron density distribution in the crystal structure, and thus allows us to identify the structure of molecules in the solid state. This technique was first introduced in the early part of the 20th century, and it has undergone many changes and improvements. Fundamental in the development of the technique has been improvement in the power of X-ray generation, in the technology of diffracted X-ray detection, and in the computer software used for processing the diffraction data and computing the image of the crystal structure. As these technologies developed, the power of the technique has improved enormously, but so has the cost. However, with high intensities, it is possible to shorten the time taken for one experiment, and with such highly productive sources it became logical to share them, and support many users who had produced crystals and needed to confirm or to know what the structure of the compound was. Accordingly, a shared facility for UK academic chemists was created in 1981, and this has been operating as a National Service since that time. The brief of the Service was to identify, acquire and operate the latest X-ray diffraction technology and make it available to users in other institutions. A major development was introduced in 2001, when access to the single crystal facility, Station 9.8, at the Daresbury Synchroton was integrated into the Service operation. This provides an incredibly high brightness X-ray beam, making it possible to study single crystals of only a few microns in size, equivalent to individual grains of a powder.For use of both the laboratory source at Southampton, and the synchrotron source, extension of the capability offered by the joint service has been possible, via the use of still developing software that can process data and resolve structures from very poor quality crystals / either with inherent growth defects or through damage due to their soft and squidgy nature. Success in handling these types of crystal, which are increasing in number, as chemists synthesise larger and more complex, fluffy molecules is crucial to the development of the chemistry of materials of current focus, and an understanding of their chemical and physical properties. The National Crystallography Service also brings together particular expertise in dealing with difficult samples that can not be investigated successfully elsewhere in the UK.