Normal Mode Flexible Fitting

NMFF is an evolving package of programs and methods that enable the flexible multi-resolution fitting of large atomically detailed structures into electron density maps from cryoEM, tomography and related lower resolution methods.The theory and methods behind NMFF are described in the papers referenced below and are based on searching along a few lowest frequency normal mode vectors, constructed from a multi-resolution elastic network representation of the atomic structure of interest, to maximize the correlation between the computed electron density for the flexible model and the experimental density.


NMFF is available for download to researchers at academic and non-profit instutions free of charge. You can download a copy the NMFF source suite by completing the licensing agreement. If you are from a commercial enterprise, if you experience problems downloading and accessing NMFF, or if you are interested in interacting with us on problems you think NMFF will be useful, please feel free to contact .


NMFF has been installed and tested on a vireity of machines including Intel/Linux, Apple/OS X and SGI/MIPS. Instructions for installing NMFF can be found here.

  NMFF Tutorials

NMFF tutorials illustrate the use of NMFF

 Publications describing NMFF

F Tama, O Miyashita and CL Brooks, III. Flexible multi-scale fitting of atomic structures into low-resolution electron density maps with elastic network normal mode analysis. Journal of Molecular Biology, 2004, 337 (4), 985-99.   PubMed

F Tama, O Miyashita and CL Brooks, III. Normal mode based flexible fitting of high-resolution structure into low-resolution experimental data from cryo-EM. Journal of Structural Biology, 2004, 147 (3), 315-26.   PubMed