PPT Slide
What is refinement?
- Refinement is the optimization of a function by changing the parameters of a model.
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What are the parameters?
- Usually everyone agrees that the parameters are the position, B factor, and occupancy of each atom.
- In most cases other parameters are added.
- In some special cases different parameters are chosen.
What is the function?
- Maximum likelihood in REFMAC, CNS, BUSTER
- Least squares in SHELX and TNT
- Empirical energy in X-PLOR, CNS