Accurate structure factors and experimental charge densities from synchrotron X-ray powder diffraction data at SPring-8
Accurate structure factors and experimental charge densities from synchrotron X-ray powder diffraction data at SPring-8
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DOI：
10.1107/s0108767306047210
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发表时间：
2007-01-01
影响因子：
1.8
通讯作者：
Sakata, Makoto
中科院分区：
文献类型：
--
作者：
Nishibori, Eiji;Sunaoshi, Eiji;Sakata, Makoto
在第三代同步辐射源SPRING-8，BL02B2上测量的粉末衍射数据，实验确定了硅和金刚石的精确结构因子。通过与文献中用Pendellosung方法测得的结构因子和一些理论计算的结构因子进行比较，对所得到的结构因子的准确性进行了评价。结果表明，从粉末数据中提取的结构因子足够准确，可以用来讨论这些材料的实验电荷密度分布。本研究确定的硅的结构因子数为104，是Pendellosung数据的三倍。根据现有的结构因子，用最大熵方法得到了实验的电荷密度。硅和金刚石键合中点的电荷密度与各种理论计算结果符合得很好。本研究证明了SPRING-8粉末衍射法是一种在更大范围内测定实验电荷密度的有前途的方法。
Accurate structure factors of silicon and diamond have been experimentally determined from powder diffraction data measured at the third-generation synchrotron-radiation source SPring-8, BL02B2. The accuracy of the obtained structure factors has been evaluated by comparing with structure factors in the literature measured by the Pendellosung method and with some from theoretical calculations. The results indicate that the structure factors from powder data are accurate enough to discuss the experimental charge-density distributions of these materials. The number of structure factors of silicon determined in the present study is 104, which is three times more than that of previous Pendellosung data. The experimental charge densities have been obtained by the maximum-entropy method from the present structure factors. The charge densities at bond mid-points for silicon and diamond show good agreement with different kinds of theoretical calculations. The present study proved that the powder diffraction at SPring-8 is a promising method for determination of experimental charge density for a wider range of materials.