phenix.fem: compute Feature Enhanced Map (FEM)

Description

The program reads PDB model, reflection data (Fobs or Iobs), experimental uncertainties and R-free flags, if available. Then it computes {2mFobs-DFmodel, Phase_model} map that is subject to FEM procedure.

Output is MTZ file with three sets of Fourier map coefficients:
  • 2mFoDFc,PHI2mFoDFc: usual {2mFobs-DFmodel, Phase_model} sigma-a weighted synthesis. No anisotropy correction or filling missing data.
  • ResolveDM,PHIResolveDM: Resolve density modified map coefficients
  • FEM,PHIFEM: Feature Enhanced Map

Command line usage examples:

% phenix.fem model.pdb data.mtz
% phenix.fem data.mtz model.pdb label=Fobs
% phenix.fem model.pdb data.mtz scattering_label=neutron

GUI

Graphical user interface is available

Additional information

Latest presentation of FEM methodology:

http://phenix-online.org/presentations/fem_SEP2013.pdf

Publication in Computational Crystallography Newsletter (front page):

http://www.phenix-online.org/newsletter/CCN_2013_07.pdf

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