Gediminas Galinis⁷, Douglas Garratt⁷, James M. Glownia⁸, Daniel Haxton¹⁰, Phay Ho⁵, Siqi Li^1,2,9, Xiang Li^8,12, James MacArthur^2,9, Jon P Marangos⁷, Adi Natan¹, Niranjan Shivaram^8,13, Daniel S. Slaughter¹³, Peter Walter⁸, Scott Wandel⁸, Linda Young^5,14, Christoph Bostedt^5,6,15, Philip H. Bucksbaum^1,2,11, Antonio Picón³, Agostino Marinelli^1,9, and James P. Cryan^1,8,†

• ¹Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
• ²Department of Physics, Stanford University, Stanford, California 94305, USA
• ³Departamento de Química, Universidad Autónoma de Madrid, 28049 Madrid, Spain
• ⁴Department of Physics, University of Connecticut, Storrs, Connecticut 06269, USA
• ⁵Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
• ⁶Paul-Scherrer Institute, CH-5232 Villigen PSI, Switzerland
• ⁷Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom
• ⁸Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
• ⁹SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
• ¹⁰KLA Corporation, Milpitas, California 95035, USA
• ¹¹Department of Applied Physics, Stanford University, Stanford, California 94305, USA
• ¹²J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, Kansas 66506, USA
• ¹³Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
• ¹⁴Department of Physics and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA
• ¹⁵LUXS Laboratory for Ultrafast X-ray Sciences, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland

• ^*Corresponding author. joneal2@stanford.edu
• ^†Corresponding author. jcryan@slac.stanford.edu