Three-dimensional Electron Microscopy (3DEM) is becoming a key experimental method in Structural Biology. Recent advances in image acquisition and processing are yielding more structures determined at near-atomic resolution, as well as a wide range of macromolecular complexes and subcellular architectures determined at lower resolution.

A major goal of the Unified Data Resource for 3DEM team is to work with the 3DEM community to establish data validation methods that can be used in the structure determination process, define key indicators of a well-determined structure that should accompany every structure deposition, and implement appropriate validation procedures into a 3DEM validation pipeline. Following recommendations of the EM Validation Task Force (Henderson et al 2012), we are hosting new benchmark challenges, with aim to stimulate further community discussions about validation procedures for 3DEM maps and map-derived models. Prior community-organized 3DEM challenge activities have included a Particle Picking Challenge (Zhu et al 2004),  CryoEM Modeling Challenge (Ludtke et al 2012), and CTF Challenge (Marabini et al 2015).