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Individual B-Factor Refinement

    This statement optimizes individual (restrained) isotropic B-factors. Distinctions between backbone and side-chain B-factor restraints can be made by appropriate selections. B-factors of atoms are both selected in xrefin and free to move. The procedure minimizes the target function

where the restraining term is given by

The summations are carried out over all bond and angle terms present in the molecular structure that involve selected and free atoms. The last sum is used only if non-crystallographic symmetry restraints are present (see Chapter 16). The Powell conjugate gradient minimization method is used.

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