This is a directory to scientific software that is freely available to the academic community. Most of our developments are concerned with postprocessing of cryo-EM maps and atomic model refinement using cryo-EM data. Please visit the individual pages for more details if you are interested. Also included is a collection of potentially useful jiffys and tools for cryo-EM model building. Currently, all projects are hosted by the EMBL Gitlab instance.


Schematic illustration of the LocScale map sharpening
Schematic illustration of the LocScale map sharpening

LocScale is a reference-based local amplitude scaling tool using prior model information to improve contrast of cryo-EM density maps. It can be helpful in the common case of resolution variation in the 3D reconstruction and it can be used as an alternative to other commonly applied map sharpening methods.

LocScale has been developed at EMBL jointly with Carsten Sachse.

LocScale is freely available under the BSD licence. For more information as well as download/installation instructions please visit the Gitlab repository at EMBL. Tutorial files and a detailed description of use and best practices are available on the Wiki pages.

eLife 6:e27131 (2017)     | doi |  


rsref is a scripted modular workflow for the refinement of atomic models against high-resolution cryo-EM density maps. It is a not a standalone refinement software, but rather provides a set of tools for model and/or map manipulation, refinement protocols, the analysis of the refinement cycles and validation of the resulting coordinate models.

rsref makes use of the libraries from the cctbx project.

rsref is an ongoing development and not officially released. If you are fine with limited support, please see the Wiki pages for dowload and usage instructions and tutorial.

If rsref is useful for you work please acknowledge the cctbx project (doi).


Local electron affinity mapped onto the isodensity surface of a caprolactam derivative inhibitor
Local electron affinity mapped onto the isodensity surface of a caprolactam derivative inhibitor

ParaFrag is a method for atom-independent bioisoster searching of molecular fragments. The approach is based on similarity comparison of local surface property extrema calculated on isodensity surfaces by semi-empirical molecular orbital methods. The method has been applied for applications in drug design (scaffold hopping). Please see here for additional information.

ParaFrag has been developed together with Timothy Clark (Computer Chemistry Center, Erlangen) and Harald Mauser (F.Hoffmann-La Roche, Basel).

ParaFrag is distributed as part of the ParaSurfTM package by Cepos InSilico. It requires a semi-empiricial molecular orbital program such as VAMP, EMPIRETM or Mopac6.

J Mol Model 14:547-558 (2008)     | doi |  


A restricted version of ParaSurfTM and EMPIRETM is freely available for bona fide academic users (register).

Script collections

  • Collection of tools & scripts for model building and refinement - link