这项工作是在GeoSoilEnviroCARS（部门13），伙伴至尊晶体程序（PX ^ 2），先进光子源（APS）和阿贡国家实验室进行的。 GeoSoilEnviroCARS是由美国国家科学基金会地球科学（EAR-1128799）和能源地质系（DE-FG02-94ER14466）的支持。在PX ^ 2计划是由美国国家科学基金会根据合作协议EAR 11-57758压缩模式的支持。先进光子源的用途由能源，科技，基础能源科学办公室的办公室的美国能源部合同号DE-C02-6CH11357支持。在压缩模式，GSECARS气体装载系统的使用是由美国国家科学基金会根据合作协议EAR 11-57758压缩模式，并通过NSF资助EAR-1128799和能源部授予的DE-FG02-94ER14466 GSECARS支持。我们也想在亚利桑那大学的谢教授RT为丘陵敬请从RRUFF藏品提供样品。

1.样品制备注:样品制备过程包括三个主要步骤:准备空的DAC，加载样品并装入惰性气体压力传递介质。 DAC制备和样品加载已经详细在拉维纳等人进行了描述。 10，和压力传递介质装载已在河流等人进行了描述。 14在这里，我们简要地描述了典型的样品制备过程。 <ol><li> 选择一对锥形钻石相匹配的背板。 <ol><li>确保金刚石砧块（culets）的平坦提示是彼此相同。 注:底尖的直径取决于实验的目标的最大压力。 </li><li>确保背板的锥形壳体的锥形钻石的形状相匹配。确保该钻石的高度，钻石的背面侧的直径，openin背板和DAC的开口角克角是彼此相容，从而最大限度地为衍射9,15角访问。 </li></ol></li><li>清洁在丙酮超声波浴钻石和背板3-5分钟。设置超声波清洗，以"声"模式。检查在光学显微镜下的钻石和背板，并删除所有可见的灰尘或碎屑。 </li><li>放置在背板的锥形壳体的钻石，和在一个安装夹具的装配。 </li><li>施加载荷的几公斤到钻石与压缩螺钉，使得它与所述背衬板的紧密接触。然后，应用约0.1g环氧树脂围绕钻石的外周。加热该组件至70℃8小时，以固化环氧树脂。 </li><li>清洁的DAC，背衬板，用丙酮钻石的culets的后侧的内部，并放置在背板与在DAC钻石。 </li><li> Adjus吨，持有垫板到位，从而使砧culets同心，当两个对立的钻石接触螺丝钻石的位置。 </li><li>检查两个culets在光学显微镜下寻找干涉条纹之间的倾斜角。调节由菱形的倾斜角度的微调的螺钉的负载，从而使条纹的数量最小化10。 </li><li>将一块两颗钻石之间的250微米厚的铼（Re）金属箔，并用蜡的地方修复它。 注意:此重新箔充当DAC的垫圈。 </li><li>通过拧紧DAC的四个压缩螺钉均匀地慢慢施加载荷，并通过测量在DAC组件的总厚度监视重新垫片用千分尺的厚度变化。 </li><li>当重新密封垫的厚度为〜40微米，取出的缓慢压缩螺钉的负载，并取出预缩进垫片。 </li><li>使用拉斯呃铣床在预压痕，其直径底尖直径至少2/3的中心钻一个孔。对准用光学显微镜的垫圈，以及设置在激光铣床用户界面衬垫孔的预定直径。按"扫描"按钮，钻洞。 </li><li>浸泡钻取垫圈到丙酮中，并与在正常模式中的超声波清洗机清洗。清洁用丙酮钻石的culets。放置在DAC钻孔垫片回来。 注:在该垫圈的孔用作样品腔室。 </li><li>放置一个单晶样品在垫圈孔，这也应该是金刚石底尖的中心的中心。 注意:最佳样本大小为20微米×20微米×5微米（长×宽×厚度）。 </li><li>放置一个小红宝石球（〜10微米的直径）靠近样品。 注:红宝石球作为压力标记。 </li><li>放置在DAC里面T的检他压缩模式/ GSECARS气体装载容器和负载压缩氦（He）或氖（Ne）气，以填充容器14约25,000 psi的最大压力。 </li><li>通过拧紧DAC的压缩螺钉增加DAC采样室内部的压力，并监视有红宝石荧光16的压力。 </li></ol> 2，数据收集<ol><li>地方〜1毫克的LaB 6粉末在衍射仪的旋转中心，并在几个MARCCD检测器的位置由δ角变收集粉末衍射图案。通过点击MARCCD EPICS界面中的"开始"按钮收集粉末衍射图案。使用这个衍射图案来校准检测器样品距离和MARCCD检测器2的倾斜。 </li><li> 在完成检测校准后，从衍射仪实验室6个标准。放置在DAC样品架，并把它放在日Ë衍射仪的样品台。 <ol><li>使用钳型保持器保持环境温度的DAC，用于高温的DAC水冷钳型保持器，并安装在ACA / IUCr标准测角计头上，以保持在环境压力和温度的样品聚合物微筛孔。 注意:在下面的步骤（2.3-2.8），所有的运动控制是与EPICS用户界面（EUI）来实现的。 </li></ol></li><li>以使样品室垂直于观察变焦摄像机通过设置的EUI的φ角度120旋转φ轴。 </li><li>首先发现在最小倍率与观看照相机的样品室中。通过改变样品的X，Y和Z的EUI居中样本的图像。通过改变EUI显微镜ž重点样本的图像，然后放大，到最大放大倍率。 </li><li>通过改变样品的X，Y和Z在E对准样品腔室的图像对观看照相机的中心UI。调节沿相机的轴线样本位置，直到它处于焦点（使用预先确定的相机聚焦来估计的旋转中心的在这个方向上的位置）。然后，使样品室垂直于入射的X射线束转动的EUI的φ角至90。 </li><li>为了校正从沿DAC的轴线仪器的中心样本的位移，扫描DAC的位置在垂直于使用SCANW软件入射的X射线的水平和垂直方向，使用内置于测角器机动的翻译，同时收集发射束用光电二极管检测器的强度数据放置在样品后面。 注:光电二极管检测器被安装在一个气动致动器，并且可以在与出光束的远程从控制站移动。 </li><li>发现使用SCANW的"中心"功能中所收集的强度扫描的中心位置，对应于最大传输。这是策样品室的NTER。 </li><li>通过使用EUI几度使用测角φ轴线旋转样品，并重复垂直透射扫描。重复扫描两次，在正反两方面的φ偏移。 </li><li>计算沿入射的X射线的方向上的样本位置与下面的等式17 <img alt="式（1）" src="/files/ftp_upload/54660/54660eq1.jpg" /> 其中，ΔY是沿入射的X射线的方向，该样品从仪器的中心移动的距离，Δφ是在扫描之间的φ角度的变化，ΔSX +和ΔS 的x是X射线的传播的位置偏移当φ角由+Δφ和-Δφ倾斜的轮廓。 注:扫描的若干迭代可以制成提高样品定位的精度。 </li><li> 样本调整后，收集的单晶衍射数据与CCD_DC软件1。 <ol><li>首先，收集φ扫描用的光电二极管通过点击SCANW软件的"扫描"键，以确定最大开启角度，并确定的金刚石砧和背板的吸收效果的功能性形状。 </li><li>的φ扫描后，进行了广泛φ曝光（在此期间，而φ旋转时，检测器保持打开），以覆盖最大打开角度为DAC允许，接着通过一系列步骤φ曝光，每个覆盖1°。执行此步骤通过设置"总范围"到最大打开角度，并且设置"步数"，以在CCD_DC软件相同的编号。通过指定在CCD_DC软件的δ和ν方向检测器臂位置收集在不同的检测器的位置宽φ扫描，以便允许接触到更多的衍射峰。 注:对于一个单位的晶体还建议细胞大于10埃，10°覆盖相同的角度范围宽步扫描集合。曝光时间由从钻石的吸收确定的，和衍射的强度从样品提供。通常选择最大化的衍射峰的强度，而不饱和度的曝光时间。一个典型的曝光时间为1-5秒/度。从一个检测器位置上的一个晶体和一个压力典型的数据采集时间约30分钟。 </li></ol></li></ol> 3.数据分析注:数据分析进行了使用ATREX / RSV软件套件2,18。用于在软件中使用的原理的详细说明，请参阅德拉等人的工作。 2 <ol><li> 过程中，实验6校准文件。 <ol><li>在打开在s每个探测器的位置采集的实验6粉末衍射图像oftware。输入入射X射线（0.434埃）的波长，然后按"细化校准"按钮。 注:该软件将自动计算出样品 - 检测器距离和检测器的倾斜相对于入射的X射线束。检测器校准仅在检测器位置ν= 0进行的，δ0 =。在非零ν和δ收集的校准图像被用于校准质量的验证。 </li><li>通过根据需要手动编辑ν和δ设置保存每个探测器的位置校准文件。 注:每个图片系列相关ATREX店检测校准.CAL文件。当打开图像，程序检查如果相关.CAL文件是否存在。如果不是，则选择这样的文件的选项。 </li></ol></li><li>保存校准所有探测器的位置后，通过检查ATREX软件"分配CAL"复选框创建这些关联，因此，该方案将记得要使用的校准。 </li><li> 搜索样品的衍射峰，并且适合峰强度。 <ol><li>打开软件中的宽角φ曝光。转到"搜索"面板，然后搜索在广角曝光的衍射峰。手动删除从钻石靠近重新垫圈环中的过饱和衍射峰与衍射峰。 </li><li>适合的衍射峰得到他们的准确位置和强度。搜索样品的衍射峰通过点击软件中的"峰值搜索"按钮，所有的检测位置，并点击"保存峰"按钮来保存相应的峰值表。 </li></ol></li><li> 重建的衍射峰"倒易空间分布。 <ol><li>在节目中，打开该峰表为一个检测器的位置，并且一个图像在步骤φ扫描，这是一个ssociated具有相同的检测器的位置。如果检测校准文件还没有被分配到这个文件系列，选择适当的.CAL文件。转到"扫描"面板，以及"从扫描计算教授"按钮按下。 注意:此步骤会发现在该峰强度是最强的各衍射峰的φ角。 </li><li>保存生成的峰值表.pks文件。重复此步骤，为所有在不同的检测位置的广泛旋转图像。 </li></ol></li><li> 指数的衍射峰。 <ol><li>使用RSV软件，打开第一个峰值表文件。使用"附加"功能合并所有附加峰表。使用RSV插件来找到这个晶体的衍射峰的，并索引初步UB矩阵。该软件会自动搜索最有可能的UB矩阵。 </li><li>通过导入.p4p文件打开RSV初步UB矩阵，完善与布法罗矩阵使用"缩小W / D-SPAC"按钮各衍射峰的d-间隔。如果晶体的对称性是已知的，选择合适的晶系的约束。 注意:当细化收敛，优化UB矩阵和晶体（A，B，C，α，β和γ）的晶格参数被确定。 </li><li>保存优化UB矩阵作为.ub文件。 注:在最初的峰值搜索过程中，程序可能会错过一些低强度峰，将在结构测定非常有价值的。 </li></ol></li><li>为了寻找这些丢失的峰回到软件，并打开广角φ曝光图像（相关校准文件应该会自动加载）。 </li><li>在"预测"面板中，打开的水晶矩阵UB和模拟衍射图样。在"峰"面板中，搜索观察到的衍射峰，并删除未观察到峰（旁边的文本框中到"看"按钮，允许指定需要的峰的峰拟合框内的最小像素强度阈值被认为是"观察"）。通过点击"高峰契合"按钮，适合峰的位置和强度，然后保存峰值表。 </li><li>合并所有在用使用"追加"功能RSV软件不同的检测位置的预测峰值表。如果不同的曝光设定（在°/秒的旋转速度）被使用，打开新的.pks文件时使用合适的缩放因子。 </li><li>导出合并的峰表作为.hkl文本文件，它可以用来缩小与SHELX软件包的晶体结构。与SHELX进行结构精修的详细过程都得到了很好别处19,20描述。 </li></ol>

<ol>
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C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-pressure+behavior+of+space+group+P2/n+omphacite.">High-pressure behavior of space group P2/n omphacite.</a> Am Mineral. 97 (2-3), 407-414 (2012).</li><li>Angel, R. J., Bujak, M., Zhao, J., Gatta, G. D., Jacobsen, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effective+hydrostatic+limits+of+pressure+media+for+high-pressure+crystallographic+studies.">Effective hydrostatic limits of pressure media for high-pressure crystallographic studies.</a> J Appl Crystallogr. 40, 26-32 (2007).</li><li>Mccormick, T. C., Hazen, R. M., Angel, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compressibility+of+Omphacite+to+60+Kbar+-+Role+of+Vacancies.">Compressibility of Omphacite to 60 Kbar - Role of Vacancies.</a> Am Mineral. 74 (11-12), 1287-1292 (1989).</li><li>Srajer, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extraction+of+accurate+structure-factor+amplitudes+from+Laue+data:+wavelength+normalization+with+wiggler+and+undulator+X-ray+sources.">Extraction of accurate structure-factor amplitudes from Laue data: wavelength normalization with wiggler and undulator X-ray sources.</a> J Synchrotron Radiat. 7, 236-244 (2000).</li><li>Tschauner, O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Discovery+of+bridgmanite,+the+most+abundant+mineral+in+Earth,+in+a+shocked+meteorite.">Discovery of bridgmanite, the most abundant mineral in Earth, in a shocked meteorite.</a> Science. 346 (6213), 1100-1102 (2014).</li><li>Dera, P., Weidner, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Mineral Physics 2016 Long-range Planning Report: Harnessing the Extremes: From Atoms and Bonds to Earthquakes and Plate Tectonics. , (2016).</li><li>Rothkirch, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-crystal+diffraction+at+the+extreme+conditions+beamline+P02.2:+procedure+for+collecting+and+analyzing+high-pressure+single-crystal+data.">Single-crystal diffraction at the extreme conditions beamline P02.2: procedure for collecting and analyzing high-pressure single-crystal data.</a> J synchrotron rad. 20 (5), 711-720 (2013).</li><li>Merlini, M., Hanfland, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-crystal+diffraction+at+megabar+conditions+by+synchrotron+radiation.">Single-crystal diffraction at megabar conditions by synchrotron radiation.</a> High Pressure Res. 33 (3), 511-522 (2013).</li></ol>

作者宣称没有利益冲突。

在这份报告中，我们显示在GSECARS 13-BM-C光束线开展与DAC的单晶衍射实验的详细过程。 BX-90型DAC，带有BA型钻石砧和背板被推荐为单晶衍射实验2,9,15。在BX-90型DAC的优点是相对于传统的对称数模转换器，它提供了许多衍射峰9,15的有效采样其更宽的角度的访问。广角访问成为具有较低对称的样品和具有较小单元电池关键:前者需要更多的衍射峰准确地约束晶格参数，而后者给定角访问2内更少的衍射峰。越角门禁一体到达实验中，更精确的原子位置参数中的一个措施2,4。限制角访问可能会导致二维倒数矢量数据集，麦ING可靠的资料解释数学上是不可能2。 其中一个重要的，但常常被忽视的一步是选择合适的传压介质。虽然压力介质，诸如氩气，硅油或甲醇-乙醇-水的溶液中以前单晶衍射实验中使用的不超过10 GPA 21-23，这些压力介质成为显著非静力5-10 GPA 22之间，并大大降低了晶体的压缩2,22中的质量。我们一般的经验是，只有他和氖导致高品质的实验高达50 GPA（ 例如 ，参考6,7）。在APS中，这些气体可以方便地装入与使用GSECARS /压缩模式气体加载装置14的DAC。当He或Ne被选择作为压力介质，样品室的气体负载（ 图2）期间收缩。一旦样品直接接触垫片，它在压缩过程中容易破碎。因此钻一个足够大的样品室，其直径为底尖直径的至少2/3，以避免在样品和气体负荷后垫圈之间的接触是重要的。 在PX ^ 2基于同步单色单晶衍射的设置是独一无二的。相比于实验室衍射仪，同步加速器X射线源提供高得多的通量（&gt; 10 4）4,27,28，其显著提高了信噪比并降低了数据采集时间4,27,28。同步加速器基粉末衍射通常也用来确定在通过的Rietveld方法4高的压力的材料的结构。单晶衍射具有优势在特维德的办法，因为它分离的晶格参数和结构参数2,4配件。与通常特维德装修粉末衍射需要配件都纬度<html>蒂斯参数，并在同一时间结构参数，而独立观察的数目通常比在单晶衍射4低得多。另一种常见的结构测定方法是劳厄衍射，它使用多色辐射与区域检测器4。相比于PX ^ 2单色数据收集，劳厄法数据的减少需要额外的条件，包括谐波去卷积和强度归一化，这增加了额外的困难在数据分析4,24。单色单晶衍射是解决结构的简单的方法，但它有其自身的局限性。单色单晶衍射的一个理想的数据集需要具有大小几十μm的一个缺陷少的晶体，并在晶体质量需要在高压下保存。这些要求可能难以满足对某些非淬火矿物质，如bridgmanite 25。 内容"&gt;时间分辨单晶衍射能够在压力引起的结构转变捕获瞬态亚稳状态和相变动力学，并且是未来的研究方向为PX之一^ 2 26的缺陷和晶格动力学，定量定性的基础上分析X射线在高压下漫散射也正在开发的PX ^ 2 26，激光加热高压单晶衍射紧凑的光学平台正在建设，并将使地球科学界研究的行为深土条件下26的材料。

单晶X-射线衍射是最有效的和公认的方法来确定在不同的实验条件下的结晶材料的化学组成和结构中的一个。最近有在高压单晶衍射发展一批1-5。压力是影响的行为和地球和行星材料的特性的主要因素之一。高压实验常规揭示普通材料的新多晶型物和可以发现的方法来合成它们不可能使在环境条件下的化学品。最近，几个新的晶型硅已确定用高压单晶衍射，从而提供新的洞察地幔6-8的属性。 从在大气压下单晶衍射不同，高压单晶衍射需要一个压力容器，以产生并保持数据收集过程中的压力。在高压单晶衍射最常用的压力容器是钻石砧细胞（DAC），它是由一对由金属框架/金属垫片保持在一起的金刚石砧的，以及一个压力传递介质，以提供静水环境中的样品室4,9-11。用金刚石砧电池单晶衍射从不同的衍射在几个重要方面的环境条件。首先，倒易空间的覆盖率显著由于通过DAC和背衬片的身体限制的X射线的角度存取降低。第二，由钻石和背板的X射线的角度依赖性吸收必须被确定并用于校正衍射信号，使得准确结构因素可以计算出来的。第三，与从DAC部件，如钻石，垫圈和压力transmittin散射或衍射样品的衍射信号的任何重叠摹中，必须消除。第四，在DAC的样品对准测角器的中心是困难的。垂直于DAC的负载轴的方向总是由垫圈阻止，并且不向任一光学显微镜或X射线束访问。在轴向方向上，在光学显微镜只能形象化因为金刚石的高折射率的样品的位移的图像。这些差异需要新的高压单晶衍射测量方法的发明。 该伙伴关系的极端Xtallography（PX ^ 2）项目是一个新的研究项目，致力于高压单晶衍射的DAC。该项目是在GeoSoilEnviroCARS实验站13-BM-C在APS，它提供了大部分的基础设施，包括检测器托管，聚焦X射线和一个6圆重型衍射仪12,13为各种先进晶体experime优化NTS。衍射仪具有六个角自由度，四个采样-定向（μ，η，χ，φ）和两个检测器，定向（δ和υ）。从你13的角约定用来描述样本和检测器的运动，虽然η，χ，φ运动是从乐器的卡伯几何真实马达衍生的伪角度。实验程序已经用于与DAC的高压单晶衍射优化，数据处理和分析软件包一个包已经被开发出来。在这个手稿中，我们提出了使用BX-90型DAC 9典型的高压单晶衍射实验的详细协议，为指导，以收集和PX ^ 2分析数据。

<table><tbody><tr><td>Diamond</td><td>Almax</td><td>P01037</td><td>Boehler-Almax type diamond</td></tr><tr><td>Backing plate</td><td>Almax</td><td>P01289</td><td>Backing plate&#039;s design should match the diamond&#039;s design</td></tr><tr><td>Re gasket</td><td>Alfa Aesar</td><td>10309</td><td></td></tr><tr><td>Epoxy</td><td>Henkel Loctite</td><td>Stycast 2651</td><td></td></tr><tr><td>Polymer micromesh</td><td>MiTeGen</td><td>M3-L18SP-25</td><td></td></tr><tr><td>Goniometer head</td><td>Hampton Research</td><td>HR4-647</td><td></td></tr><tr><td>Software: ATREX</td><td>Open source software</td><td></td><td>Website: https://github.com/pdera/GSE_ADA</td></tr><tr><td>Software: RSV</td><td>Open source software</td><td></td><td>Website: https://github.com/pdera/RSV</td></tr><tr><td>Software: cell_now</td><td>Bruker Corporation</td><td></td><td></td></tr><tr><td>Software: CCD_DC</td><td>Free software</td><td></td><td></td></tr></tbody></table>

high pressure single crystal diffraction at px^2

在这份报告中，我们描述了与在先进光子源的GSECARS 13-BM-C光束线金刚石压腔（DAC）进行单晶X射线衍射实验的详细过程。在13-BM-C DAC的方案是伙伴极端Xtallography（PX ^ 2）项目的一部分。 BX-90型DAC，带有圆锥型钻石砧和背板被推荐用于这些实验。样品室应与稀有气体被加载以保持静水压力的环境。将样品对准衍射测角器的旋转中心。该MARCCD区域检测器被校准以从实验6的粉末衍射图案。样品的衍射峰进行了分析与ATREX软件程序，并随后与RSV软件程序索引。 RSV被用来细化单晶的UB矩阵，并用此信息与峰值预测功能，更衍射峰可以位于。代表从绿辉石单晶衍射数据（钙0.51 0.48钠）（镁0.44 0.44铝的 Fe 2+ 0.14铁3+ 0.02）硅收集2 O 6个样品。数据分析在0.35 GPA给出了与P2 /正空间群单斜晶点阵，并且发现了晶格参数为:α= 9.496±0.006，A，B = 8.761±0.004埃，C = 5.248±0.001埃，β= 105.06±0.03º，α=γ= 90°。

我们展示的硅酸盐矿物绿辉石的高压单晶衍射的一个代表性的例子（钙0.51 0.48钠）（镁0.44 0.44铝的 Fe 2+ 0.14铁3+ 0.02）的Si 2 O 6。该绿辉石样品与伯勒尔-ALMAX（BA）型金刚石砧和背板（ 图1）一个BX-90型的DAC加载。样品室被填充有贵金属的废气压力（在此情况下氦）传递介质，以确保一个静水压力的环境。样品室的压力为0.35 GPa时由红宝石荧光测定。样品用衍射测角器的旋转中心（ 图3,4）对齐。我们校准在ν= 0 MARCCD检测器的位置和倾斜，δ= 0用的LaB 6粉末标准（ 图5）。在实验期间，η，`7;和μ角，在0固定样品的衍射峰的第一利用ATREX软件的"搜索"功能（ 图6）进行分析。然后，晶格参数和绿辉石单晶的UB矩阵使用RSV软件（ 图7）进行了细化。与晶体的精制UB矩阵，使用该软件的"预测"功能（ 图8）被发现更多的衍射峰。在此压力下此绿辉石单晶的精制晶格参数为:a = 9.496±0.006，A，B = 8.761±0.004埃，C = 5.248±0.001埃，β= 105.06±0.03º，α=γ= 90°（表1）。该绿辉石晶体，发现有在P 2 / N空间群单斜晶格。我们细化晶格参数与绿辉石的出版晶格参数与一致相似的化学成分，并以类似的压力为:P = 0.449 GPa时α= 9.5541±0.0005，A，B = 8.7481±0.0007 A，C = 5.2482±0.0003埃，β= 106.895±0.004º21。 <img alt="图1" src="/files/ftp_upload/54660/54660fig1.jpg" /> 图1:这是用于高压单晶衍射BX-90 DAC的组成部分。 （ 一 ）伯勒尔-ALMAX（BA）型钻石; （b）重新垫片; （ 三 ）BA型背板; （ 四 ）BA型金刚石粘在BA型背板; （e）该BX-90的DAC的筒部; （ 六 ）BX-90的DAC的活塞部分; （G）左手（黑色氧化表面处理）和右手（不锈钢精加工）压缩螺丝:（H）右手磁盘弹簧垫圈压缩螺杆; （ <str翁&gt;我）BX-90装配DAC准备高压单晶衍射实验。 <a href="http://ecsource.jove.com/files/ftp_upload/54660/54660fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/54660/54660fig2.jpg" /> 图2: 前和惰性气体压力传递介质加载后DAC采样室的显微镜图像。气体压力传递介质装载后，将样品室孔的直径缩小了〜30％。 <a href="http://ecsource.jove.com/files/ftp_upload/54660/54660fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图3" src="/files/ftp_upload/54660/54660fig3.jpg" /> 图3: 用于高预实验装置ssure在PX ^ 2单晶衍射。六个角自由度（μ，η，χ，φ，δ和υ）和三个平移方向（x，y和z）的被标记。对于角度的符号如下您13的角度约定。 <a href="http://ecsource.jove.com/files/ftp_upload/54660/54660fig3large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图4" src="/files/ftp_upload/54660/54660fig4.jpg" /> 图4: 校准样品室的旋转中心。左:在X射线的正常方向（蓝色）和φ旋转了+Δφ（绿色）和-Δφ（红色）样品室扫描。右:在不同φ角度样品室扫描X射线透射轮廓。的X射线透射剖面的偏移量被用于沿inciden计算位置修正<html> ŧX射线的方向。 <a href="http://ecsource.jove.com/files/ftp_upload/54660/54660fig4large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图5" src="/files/ftp_upload/54660/54660fig5.jpg" /> 图5: 校准使用数据分析软件中的MARCCD检测器。的LaB 6粉末衍射图案用来进行校准。 <a href="http://ecsource.jove.com/files/ftp_upload/54660/54660fig5large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图6" src="/files/ftp_upload/54660/54660fig6.jpg" /> 图6: 用数据分析软件的衍射峰的搜索。在总共63衍射峰广本曝光的图片中发现。<html> S / ftp_upload / 54660 / 54660fig6large.jpg"目标="_空白"&gt;点击此处查看该图的放大版本。 <img alt="图7" src="/files/ftp_upload/54660/54660fig7.jpg" /> 图7: 索引的衍射峰，并计算使用RSV软件样品的UB矩阵。索引是由软件自动进行。 <a href="http://ecsource.jove.com/files/ftp_upload/54660/54660fig7large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图8" src="/files/ftp_upload/54660/54660fig8.jpg" /> 图8: 预测与数据分析软件的衍射峰。 112衍射峰在图6中被发现具有相同的衍射图像与使用峰值预测功能。COM /文件/ ftp_upload / 54660 / 54660fig8large.jpg"目标="_空白"&gt;点击此处查看该图的放大版本。 <table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody><tr><td>晶格参数</td><td>值</td></tr><tr><td>一个</td><td> 9.496±0.006 </td></tr><tr><td> b </td><td> 8.761±0.004 </td></tr><tr><td> C </td><td> 5.248±0.001 </td></tr><tr><td>一个</td><td> 90º </td></tr><tr><td> b </td><td> 105.06±0.03º </td></tr><tr><td> G </td><td> 90º </td></tr></tbody></table> 表1:绿辉石的晶胞参数（钙 0.51 0.48 钠 ）（镁 0.44 0.44 铝 铁 &lt;STRONG&gt; 2 + 0.14 铁 3+ 0.02）的Si 2 O 6 0.35 GPA。该绿辉石晶体，发现有在P 2 / N空间群单斜晶格。

Watch this Scientific Journal Video about High Pressure Single Crystal Diffraction at PX^2 at JoVE.com

High Pressure Single Crystal Diffraction at PX^2

在这份报告中，我们描述了在以先进光子源的GSECARS 13-BM-C光束线与金刚石压腔进行单晶X射线衍射实验的详细过程。 ATREX和RSV程序用于分析数据。

高压单晶衍射PX ^ 2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the ...

high-pressure-single-crystal-diffraction-at-px2

Universidad de Cartagena UDEC

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JoVE Journal

Chemistry

21.4K 次观看.  University of Hawai’i at Manoa. 在这份报告中，我们描述了在以先进光子源的GSECARS 13-BM-C光束线与金刚石压腔进行单晶X射线衍射实验的详细过程。 ATREX和RSV程序用于分析数据。 

视频: High Pressure Single Crystal Diffraction at PX^2

Synthesis and Microdiffraction at Extreme Pressures and Temperatures

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary interiors, design materials with novel properties, understand the mechanical behavior of materials exposed to very high stresses as in explosions or impacts. Synthesis and structural analysis of materials at extreme conditions of pressure and temperature entails remarkable technical challenges. In the laser heated diamond anvil cell (LH-DAC), very high pressure is generated between the tips of two opposing diamond anvils forced against each other; focused infrared laser beams, shined through the diamonds, allow to reach very high temperatures on samples absorbing the laser radiation. When the LH-DAC is installed in a synchrotron beamline that provides extremely brilliant x-ray radiation, the structure of materials under extreme conditions can be probed in situ. LH-DAC samples, although very small, can show highly variable grain size, phase and chemical composition. In order to obtain the high resolution structural analysis and the most comprehensive characterization of a sample, we collect diffraction data in 2D grids and combine powder, single crystal and multigrain diffraction techniques. Representative results obtained in the synthesis of a new iron oxide, Fe4O5 1 will be shown.

The laser heated diamond anvil cell combined with synchrotron micro-diffraction techniques allows researchers to explore the nature and properties of new phases of matter at extreme pressure and temperature (PT) conditions. Heterogeneous samples can be characterized in situ under high pressure by 2D mapping and combined powder, single-crystal and multigrain diffraction approaches.

在极端的压力和温度的合成和Microdiffraction

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary ...

科研

工程学

X-ray Powder Diffraction in Conservation Science: Towards Routine Crystal Structure Determination of Corrosion Products on Heritage Art Objects

The crystal structure determination and refinement process of corrosion products on historic art objects using laboratory high-resolution X-ray powder diffraction (XRPD) is presented in detail via two case studies.
The first material under investigation was sodium copper formate hydroxide oxide hydrate, Cu4Na4O(HCOO)8(OH)2&#8729;4H2O (sample 1) which forms on soda glass/copper alloy composite historic objects (e.g., enamels) in museum collections, exposed to formaldehyde and formic acid emitted from wooden storage cabinets, adhesives, etc. This degradation phenomenon has recently been characterized as &#34;glass induced metal corrosion&#34;.
For the second case study, thecotrichite, Ca3(CH3COO)3Cl(NO3)2&#8729;6H2O (sample 2), was chosen, which is an efflorescent salt forming needlelike crystallites on tiles and limestone objects which are stored in wooden cabinets and display cases. In this case, the wood acts as source for acetic acid which reacts with soluble chloride and nitrate salts from the artifact or its environment.
The knowledge of the geometrical structure helps conservation science to better understand production and decay reactions and to allow for full quantitative analysis in the frequent case of mixtures.

Modern high resolution X-ray powder diffraction (XRPD) in the laboratory is used as an efficient tool to determine crystal structures of long-known corrosion products on historic objects.

X射线粉末衍射在保护科学:迈向文物艺术品腐蚀产物的常规晶体结构测定

The crystal structure determination and refinement process of corrosion products on historic art objects using laboratory high-resolution X-ray powder ...

化学

Fully Autonomous Characterization and Data Collection from Crystals of Biological Macromolecules

High-brilliance X-ray beams coupled with automation have&#160;led to the use of synchrotron-based macromolecular X-ray crystallography (MX) beamlines for even the most challenging projects in structural biology. However, most facilities still require the presence of a scientist on site to perform the experiments. A new generation of automated beamlines dedicated to the fully automatic characterization of, and data collection from, crystals of biological macromolecules has recently been developed. These beamlines represent a new tool for structural biologists to screen the results of initial crystallization trials and/or the collection of large numbers of diffraction data sets, without users having to control the beamline themselves. Here we show how to set up an experiment for automatic screening and data collection, how an experiment is performed at the beamline, how the resulting data sets are processed, and how, when possible, the crystal structure of the biological macromolecule is solved.

Here, we describe how to use the automated screening and data collection options available at some synchrotron beamlines. Scientists send cryocooled samples to the synchrotron, and the diffraction properties are screened, the data sets are collected and processed and, where possible, a structure solution is carried out&#8212;all without human intervention.

生物大分子晶体的完全自主表征及数据采集

High-brilliance X-ray beams coupled with automation have&#160;led to the use of synchrotron-based macromolecular X-ray crystallography (MX) beamlines for ...

生物化学

Measurements of Long-range Electronic Correlations During Femtosecond Diffraction Experiments Performed on Nanocrystals of Buckminsterfullerene

The precise details of the interaction of intense X-ray pulses with matter are a topic of intense interest to researchers attempting to interpret the results of femtosecond X-ray free electron laser (XFEL) experiments. An increasing number of experimental observations have shown that although nuclear motion can be negligible, given a short enough incident pulse duration, electronic motion cannot be ignored. The current and widely accepted models assume that although electrons undergo dynamics driven by interaction with the pulse, their motion could largely be considered &#39;random&#39;. This would then allow the supposedly incoherent contribution from the electronic motion to be treated as a continuous background signal and thus ignored. The original aim of our experiment was to precisely measure the change in intensity of individual Bragg peaks, due to X-ray induced electronic damage in a model system, crystalline C60. Contrary to this expectation, we observed that at the highest X-ray intensities, the electron dynamics in C60 were in fact highly correlated, and over sufficiently long distances that the positions of the Bragg reflections are significantly altered. This paper describes in detail the methods and protocols used for these experiments, which were conducted both at the Linac Coherent Light Source (LCLS) and the Australian Synchrotron (AS) as well as the crystallographic approaches used to analyse the data.

We describe an experiment designed to probe the electronic damage induced in nanocrystals of Buckminsterfullerene (C60) by intense, femtosecond pulses of X-rays. The experiment found that, surprisingly, rather than being stochastic, the X-ray induced electron dynamics in C60 are highly correlated, extending over hundreds of unit cells within the crystals1.

在纳米富勒的飞秒衍射实验的长程电子关联的测量

The precise details of the interaction of intense X-ray pulses with matter are a topic of intense interest to researchers attempting to interpret the ...

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050

The M42 aminopeptidases form functionally active complexes made of 12 subunits. Their assembly process appears to be regulated by their metal ion cofactors triggering a dimer-dodecamer transition. Upon metal ion binding, several structural modifications occur in the active site and at the interaction interface, shaping dimers to promote the self-assembly. To observe such modifications, stable oligomers must be isolated prior to structural study. Reported here is a method that allows the purification of stable dodecamers and dimers of TmPep1050, an M42 aminopeptidase of T. maritima, and their structure determination by X-ray crystallography. Dimers were prepared from dodecamers by removing metal ions with a chelating agent. Without their&#160;cofactor, dodecamers became less stable and were fully dissociated upon heating. The oligomeric structures were solved by the straightforward molecular replacement approach. To illustrate the methodology, the structure of a TmPep1050 variant, totally impaired in metal ion binding, is presented showing no further breakdown of dimers to monomers.

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050

This protocol has been developed to study the dimer-dodecamer transition of TmPep1050, an M42 aminopeptidase, at the structural level. It is a straightforward pipeline starting from protein purification to X-ray data processing. Crystallogenesis, data set indexation, and molecular replacement have been emphasized through a case of study, TmPep1050H60A H307A variant.

X射线晶体学研究热木体马里蒂玛M42氨基肽TmPep1050的寡聚态过渡

The M42 aminopeptidases form functionally active complexes made of 12 subunits. Their assembly process appears to be regulated by their metal ion ...

A Sample Preparation Pipeline for Microcrystals at the VMXm Beamline

The mounting of microcrystals (&#60;10 &#181;m) for single crystal cryo-crystallography presents a non-trivial challenge. Improvements in data quality have been seen for microcrystals with the development of beamline optics, beam stability and variable beam size focusing from submicron to microns, such as at the VMXm beamline at Diamond Light Source1. Further improvements in data quality will be gained through improvements in sample environment and sample preparation. Microcrystals inherently generate weaker diffraction, therefore improving the signal-to-noise is key to collecting quality X-ray diffraction data and will predominantly come from reductions in background noise. Major sources of X-ray background noise in a diffraction experiment are from their interaction with the air path before and after the sample, excess crystallization solution surrounding the sample, the presence of crystalline ice and scatter from any other beamline instrumentation or X-ray windows. The VMXm beamline comprises instrumentation and a sample preparation protocol to reduce all these sources of noise.
Firstly, an in-vacuum sample environment at VMXm removes the air path between X-ray source and sample. Next, sample preparation protocols for macromolecular crystallography at VMXm utilize a number of processes and tools adapted from cryoTEM. These include copper grids with holey carbon support films, automated blotting and plunge cooling robotics making use of liquid ethane. These tools enable the preparation of hundreds of microcrystals on a single cryoTEM grid with minimal surrounding liquid on a low-noise support. They also minimize the formation of crystalline ice from any remaining liquid surrounding the crystals. 
We present the process for preparing and assessing the quality of soluble protein microcrystals using visible light and scanning electron microscopy before mounting the samples on the VMXm beamline for X-ray diffraction experiments. We will also provide examples of good quality samples as well as those which require further optimization and strategies to do so.

The signal-to-noise ratio of data is one of the most important considerations in performing X-ray diffraction measurements from microcrystals. The VMXm beamline provides a low-noise environment and microbeam for such experiments. Here, we describe sample preparation methods for mounting and cooling microcrystals for VMXm and other microfocus macromolecular crystallography beamlines.

VMXm 光束线微晶样品制备管道

The mounting of microcrystals (&#60;10 &#181;m) for single crystal cryo-crystallography presents a non-trivial challenge. Improvements in data quality ...

Sample Preparation and Transfer Protocol for In-Vacuum Long-Wavelength Crystallography on Beamline I23 at Diamond Light Source

Long-wavelength macromolecular crystallography (MX) exploits the anomalous scattering properties of elements, such as sulfur, phosphorus, potassium, chlorine, or calcium, that are often natively present in macromolecules. This enables the direct structure solution of proteins and nucleic acids via experimental phasing without the need of additional labelling. To eliminate the significant air absorption of X-rays in this wavelength regime, these experiments are performed in a vacuum environment. Beamline I23 at Diamond Light Source, UK, is the first synchrotron instrument of its kind, designed and optimized for MX experiments in the long wavelength range towards 5 &#197;. 
To make this possible, a large vacuum vessel encloses all endstation components of the sample environment. The necessity to maintain samples at cryogenic temperatures during storage and data collection in vacuum requires the use of thermally conductive sample holders. This facilitates efficient heat removal to ensure sample cooling to approximately 50 K. The current protocol describes the procedures used for sample preparation and transfer of samples into vacuum on beamline I23. Ensuring uniformity in practices and methods already established within the macromolecular crystallography community, sample cooling to liquid nitrogen temperature can be performed in any laboratory setting equipped with standard MX tools. 
Cryogenic storage and transport of samples only require standard commercially available equipment. Specialized equipment is required for the transfer of cryogenically cooled crystals from liquid nitrogen into the vacuum endstation. Bespoke sample handling tools and a dedicated Cryogenic Transfer System (CTS) have been developed in house. Diffraction data collected on samples prepared using this protocol show excellent merging statistics, indicating that the quality of samples is unaltered during the procedure. This opens unique opportunities for in-vacuum MX in a wavelength range beyond standard synchrotron beamlines.

Here, we present a protocol for cryogenic sample preparation and transfer of crystals into the vacuum endstation on beamline I23 at Diamond Light Source, for long-wavelength macromolecular X-ray crystallography experiments.

金刚石光源下光束线I23真空长波长晶体学的样品制备和转移实验方案

Long-wavelength macromolecular crystallography (MX) exploits the anomalous scattering properties of elements, such as sulfur, phosphorus, potassium, ...

On-Chip Crystallization and Large-Scale Serial Diffraction at Room Temperature

Biochemical reactions and biological processes can be best understood by demonstrating how proteins transition among their functional states. Since cryogenic temperatures are non-physiological and may prevent, deter, or even alter protein structural dynamics, a robust method for routine X-ray diffraction experiments at room temperature is highly desirable. The crystal-on-crystal device and its accompanying hardware and software used in this protocol are designed to enable in situ X-ray diffraction at room temperature for protein crystals of different sizes without any sample manipulation. Here we present the protocols for the key steps from device assembly, on-chip crystallization, optical scanning, crystal recognition to X-ray shot planning and automated data collection. Since this platform requires no crystal harvesting nor any other sample manipulation, hundreds to thousands of protein crystals grown on chip can be introduced into an X-ray beam in a programmable and high-throughput manner.

This contribution describes how to set up protein crystallization on crystal-on-crystal devices and how to perform automated serial data collection at room temperature using the on-chip crystallization platform.

室温下的片上结晶和大规模连续衍射

Biochemical reactions and biological processes can be best understood by demonstrating how proteins transition among their functional states. Since ...

基于膦酸盐的 MOF 的合成和发现：一种溶热方法

Discovery and Synthesis Optimization of Isoreticular Al(III) Phosphonate-Based Metal-Organic Framework Compounds Using High-Throughput Methods

High-throughput (HT) methods are an important tool for the fast and efficient screening of synthesis parameters and the discovery of new materials. This manuscript describes the synthesis of metal-organic frameworks (MOFs) from solution using an HT reactor system, resulting in the discovery of various phosphonate-based MOFs of the composition [Al2H12-x(PMP)3]Clx&#8729;6H2O (H4PMP = N,N &#39;-piperazine bis(methylenephosphonic acid)) for x = 4, 6, denoted as Al-CAU-60-xHCl, containing trivalent aluminum ions. This was accomplished under solvothermal reaction conditions by systematically screening the impact of the molar ratio of the linker to the metal and the pH of the reaction mixture on the product formation. The protocol for the HT investigation includes six steps: a) synthesis planning (DOE = design of&#160;experiment) within the HT methodology, b) dosing and working with in-house developed HT reactors, c) solvothermal synthesis, d) synthesis workup using in-house developed filtration blocks, e) characterization by HT powder X-ray diffraction, and f) evaluation of the data. The HT methodology was first used to study the influence of acidity on the product formation, leading to the discovery of Al-CAU-60&#8729;xHCl (x = 4 or 6).

作者聚焦：加速微孔材料化学的发现 

The targeted synthesis of new metal-organic frameworks (MOFs) is difficult, and their discovery depends on the knowledge and creativity of the chemist. High-throughput methods allow complex synthetic parameter fields to be explored quickly and efficiently, accelerating the process of finding crystalline compounds and identifying synthetic and structural trends.

基于高通量方法的等网状Al（III）膦酸盐基金属有机骨架化合物的发现与合成优化

High-throughput (HT) methods are an important tool for the fast and efficient screening of synthesis parameters and the discovery of new materials. This ...

高压单晶衍射PX ^ 2

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此视频中的章节

在极端的压力和温度的合成和Microdiffraction

X射线粉末衍射在保护科学:迈向文物艺术品腐蚀产物的常规晶体结构测定

生物大分子晶体的完全自主表征及数据采集

在纳米富勒的飞秒衍射实验的长程电子关联的测量

X射线晶体学研究热木体马里蒂玛M42氨基肽TmPep1050的寡聚态过渡

VMXm 光束线微晶样品制备管道

金刚石光源下光束线I23真空长波长晶体学的样品制备和转移实验方案

室温下的片上结晶和大规模连续衍射

基于高通量方法的等网状Al（III）膦酸盐基金属有机骨架化合物的发现与合成优化

基于高通量方法的等网状Al（III）膦酸盐基金属有机骨架化合物的发现与合成优化