Supporting Information Orientation Resolving Pulsed Electron Dipolar High-Field EPR Spectroscopy on Disordered Solids: I. Structure of Spin-Correlated Radical Pairs in Bacterial Photosynthetic Reaction Centers A. Savitsky a , A.A. Dubinskii b , M. Flores c , W. Lubitz c , K. Möbius a,* a Department of Physics, Free University Berlin, Arnimallee 14, 14195 Berlin, Germany b Semenov Institute of Chemical Physics, Kosygin str. 4, 117977 Moscow, Russia c Max-Planck Institute for Bioinorganic Chemistry, 45413 Mülheim/Ruhr, Germany * To whom correspondence should be addressed. E-mail: moebius@physik.fu-berlin.de 1