Software update: the ORCA program system, version 4.0

This short update provides an overview of the capabilities that have been added to the ORCA electronic structure package (version 4.0) since publication of the first article in 2012. WIREs Comput Mol Sci 2018, 8:e1327. doi: 10.1002/wcms.1327 This article is categorized under: Electronic Structure Theory > Ab Initio Electronic Structure Methods Electronic Structure Theory > Density Functional Theory Software > Quantum Chemistry