Predicting catalysis: understanding ammonia synthesis from first-principles calculations. ανά Hellman, A, Baerends, E, Biczysko, M, Bligaard, T, Christensen, C, Clary, D, Dahl, S, van Harrevelt, R, Honkala, K, Jonsson, H, Kroes, G, Luppi, M, Manthe, U, Nørskov, J, Olsen, R, Rossmeisl, J, Skúlason, E, Tautermann, C, Varandas, A, Vincent, J