The role of OH− ions in the stabilization of F2+ colour centres in LiF V. M. Khulugurov, V. N. Salomatov, I. M. Kalogeras, A. Vassilikou-Dova and I. Christakis Eur. Phys. J. B, 28 1 (2002) 91-101 Published online: 09 July 2002 DOI: 10.1140/epjb/e2002-00204-0