Plots of R factors (with kisotropic = 0.0961) and the LS function (with kisotropic = 0.0863) for PDB entry 1kwn
(left) and R factors (with kisotropic = 0.0131) and the LS function (with kisotropic = 0.0151) for PDB entry 1hqw
(right), illustrating that the minima of the R-factor function (46) and the LS function (22) can be at significantly different locations in parameter space. In such cases, a line search around the value of kmask obtained by minimization of the LS function is necessary in order to obtain a value that minimizes the R factor. For plotting purposes, the values of the LS function were scaled to be similar to the R factors.