parallel toolkit for 3D reconstructions in cryo-electron microscopy

 RELION (for REgularised LIkelihood OptimisatioN) is a stand-alone
 computer program for Maximum A Posteriori refinement of (multiple) 3D
 reconstructions or 2D class averages in cryo-electron microscopy.
 .
 RELION provides a GUI, several command-line tools in parallel (MPI) and serial
 versions, optionally with CUDA/GPU support.
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 relion-cuda provides the serial and parallel (MPI) command-line tools with
 CUDA/GPU support.