Nature 555, 94–97 (2018); doi:https://doi.org/10.1038/nature25783

In this Letter, owing to an error during the production process, only author L.O.H. was listed as a corresponding author, instead of both D.G. (guodl@igsnrr.ac.cn) and L.O.H. (lhedin@princeton.edu). This has been corrected online.