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X-ray Analysis of Electron Density -Theory and Experiment-

电子密度的 X 射线分析-理论与实验-

基本信息

批准号：
09045034
负责人：
TANAKA Kiyoaki
金额：
$ 2.37万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09045034/
关键词：
X-ray diffraction Electron Density X-ray AO MO Analysis Multipole refinement Vacuum camera VCIP法 KNiFィイD23ィエD2 Perovskite X線原子軌道解析トポロジカル解析多重極解析法 X線精密解析多極子解析法結晶場 3d準位

项目摘要

The aim of the present international cooperative research is to exchange theoretical methods and experimental techniques in X-ray electron density study between researches in Russia and Japan and to Develop X-ray crystallography in the 21-st century. The methods of refinements of us in Japan and researchers in Russia are based on atomic or molecular orbitals (X-ray AO/MO analysis) and electron density (multiple refinement), respectively. The X-ray AO analysis has been successfully applied to transition metal complexes. However the X-ray MO analysis has not been successful.The electron density of perovskite KNiFィイD23ィエD2 crystals was studied because of the highest symmetry of the crystal field, in which both methods could be easily compared. It was analyzed with the both method and give almost the same electron configuration. Topological analysis of the electron density of KNiFィイD23ィエD2 revealed that the topological picture of the atomic interactions differed from that resulting from the classic crystal chemistry molecular orbital (CMO), in which the periodicity of crystals is taken into account, should be used.Highly accurate measurement is necessary for X-ray MO analysis. The VCIP method was devised to measure intensities free from the noise due to air-scattered X-rays. The VCIP measurement of KNiFィイD23ィエD2 was compared with that by a four-circle diffractometer. Both gave almost the same deformation density and R-factors were 0.4% and 0.8% for four-circle and VCIP measurements, respectively. Since slant incidence of diffracted X-rays onto IP and problems as a device for highly accurate intensity measurement in 21-st century.

本次国际合作研究的目的是交流俄罗斯和日本研究人员在X射线电子密度研究方面的理论方法和实验技术，发展世纪的X射线晶体学。我们在日本和俄罗斯的研究人员分别基于原子或分子轨道（X射线AO/MO分析）和电子密度（多重细化）的方法。X射线原子吸收光谱分析已成功地应用于过渡金属配合物的分析。但X射线MO分析并不成功，由于KNiF_xD_23_xD_2晶体具有最高的晶场对称性，因此研究了晶体的电子密度，这两种方法很容易比较。用这两种方法进行了分析，得到了几乎相同的电子构型。对KNiF晶体D23的电子密度进行了拓扑分析，发现原子间相互作用的拓扑图不同于经典的晶体化学分子轨道（CMO），CMO考虑了晶体的周期性。VCIP方法旨在测量不受空气散射X射线噪音影响的强度。比较了用四圆衍射仪和真空等离子体光化学（VCIP）法对KNiF_（23）Nd_（22）Nd_（23）的测量结果。两者给出几乎相同的变形密度，四圆和VCIP测量的R因子分别为0.4%和0.8%。由于衍射X射线斜入射到IP和问题作为一种高精度的强度测量设备在21世纪。