The protein's structure has to be refined to elucidate its biological function exactly, after it is approximately determined with the X-ray crystallography. Mathematically the conjugate gradient method is rapid and convenient to the refinement, giving the restraint in the structure as a gathering of parts of standard value. It would be possible to do the high accuracy in atomic level, because the high-quality data can have been observed.
日本結晶学会誌 48(6), 387-393, 2006-12-25
The Crystallographic Society of Japan