Correction to: Nature https://doi.org/10.1038/s41586-019-0954-4Published online 27 February 2019

In the Acknowledgements section of this Article, the statement ‘B.A.B. and Z.W. acknowledge support for the analytical work from the Department of Energy (de-sc0016239), a Simons Investigator Award, the Packard Foundation, and the Schmidt Fund for Innovative Research.’ should be replaced by ‘B.A.B. and Z.W. acknowledge support for the analytical work and ab initio calculations from the Department of Energy (de-sc0016239). B.A.B and Z.W. acknowledge additional support from a Simons Investigator Award, the Packard Foundation, and the Schmidt Fund for Innovative Research.’. The original Article has been corrected online.