Index

Protein Data Bank exchange dictionary (pdbx) version 1.0521

_reflns.pdbx_d_opt

Definition:

   The optical resolution of the data set, d(opt), is the
      expected minimum distance between two resolved peaks in
      an electron-density map.

      d(opt) = {2[sigma(Patt)2^ + sigma(sph)2^]}1/2^

      sigma(Patt) = standard deviation of the Gaussian function
                    fitted to the Patterson origin peak
      sigma(sph)  = standard deviation of the Gaussian function
                    fitted to the origin peak of the spherical
                    interference function, representing the Fourier
                    transform of a sphere with radius 1/dmin
      dmin        = nominal resolution (_reflns.d_resolution_high)

      Ref: Vaguine, A. A., Richelle, J. & Wodak, S. J. (1999).
           Acta Cryst. D55, 191-205.
           (see also http://www.ysbl.york.ac.uk/~alexei/sfcheck.html)
   Weiss, M. S. (2001). J. Appl. Cryst. 34, 130-135.

Type: float

Mandatory item: no

Category: reflns