Pseudo-energy force constants

Another important effect of pseudo-energy force constants is controlling the distribution of errors. For example, a misassigned NOE may show up as a residual violation if a small value for Kdc is used, but it may cause a distortion of the structure and high potential energy if Kdc is large. 

When making such a decision, some considerations should be borne in mind. First, if one is using a refinement scheme that produces a known distribution of structures, then one can calculate the likely deviation that the pseudo-energy terms will permit. For example, if an MD refinement is used, structures will be able to cross barriers of about BT. Then, if one is using a quadratic form to enforce distance restraints, one could recast Eq. [9] as follows to get an idea of the violations that would be permitted for a given force constant and temperature ... 

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