(REgularised LIkelihood OptimisatioN) a stand-alone computer program for Maximum A Posteriori (MAP) refinement of (multiple) 3D reconstructions or 2D class averages in cryo-electron microscopy.
RELION versions > 2.0 are GPU-accelerated using Nvidia CUDA on Linux. For general information on running GPU accelerated applications from SBGrid, please see here : https://sbgrid.org/wiki/gpu
CUDA builds of RELION are designated by a '_cu' suffix in the version of the application. For example, 3.0.8_cu8.0 is linked against CUDA v8.0 libraries. All builds are single precision on the GPU and can be run on 'consumer-grade' GPU hardware.
RELION and MPI : RELION uses the 'mpirun' executable to manage MPI ranks. SBGrid includes several OpenMPI versions, The OpenMPI mpirun executable must match the version of OpenMPI used to build RELION. For example, RELION versions 3.0.8_cu*.0 use OpenMPI version 2.1.2 and must use mpirun from OpenMPI 2.1.2 (this is the default).
3.1-beta releases use OpenMPI version 3.1.6 and require an override in $HOME/.sbgrid.conf to set the OpenMPI version to 3.1.6. Add
to $HOME/.sbgrid.conf and open a new terminal to use the correct mpirun. You can also use the 'mpirun.relion' executable in place of mpirun to use the MPI that matches the currently configured version of RELION.
20200610 : rebuild of 3.1-beta releases with OpenMPI 3.1.6 from commit 5997001
Empty values in GUI during autopicking can be interpreted as Text instead of Float values.
S. H. W. Scheres. 2012. A Bayesian View on Cryo-EM Structure Determination. J Mol Biol. 415(2): 406-418.
S. H. W. Scheres. 2012. RELION: Implementation of a Bayesian approach to cryo-EM structure determination. J Struct Biol. 180(3): 519-530.
*Full citation information available through
If RELION is useful in your work, please use at least one of the primary citations listed.