Photoionization thresholds and structures of third group metals clustered with ammonia T. M. Di Palma, A. Latini, M. Satta and A. Giardini-Guidoni Eur. Phys. J. D, 4 2 (1998) 225-229 Published online: 15 November 1998 DOI: 10.1007/s100530050203