Some B(eq) are more equivalent than others.
Some B(eq) are more equivalent than others.
复制标题
有些 B(eq) 比其他的更等价。
DOI：
10.1107/s0108767311034350
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Merritt,EthanA
中科院分区：
文献类型：
--
作者：
Merritt,EthanA
Crystallographic structural models for macromolecules have typically included an isotropic displacement parameter Biso for each atom. In cases where the structural model instead includes anisotropic displacement parameters Uij, the derived quantity Beq can be substituted for Biso for many purposes. Beq is not, however, the best predictor of the value Biso that would hypothetically have been obtained by direct refinement of an isotropic model. A new entity Best is proposed that represents an estimate for Biso that minimizes the Kullback–Leibler divergence from a paired anisotropic model. In general Best/Beq < 1, with the difference between the two values becoming larger for atoms that are more anisotropic. Although this difference does not affect direct refinement of either isotropic or anisotropic models, it is relevant to any analysis that compares isotropic and anisotropic models of the same underlying structure. In particular, it may lead to improved selection of multi-group TLS models based on analysis of an initial isotropic refinement.
