Using ab initio density functional theory total energy calculations, we study the influence of H, B, C, N, O, and S in the rupture of a gold nanowire. In particular, using an as realistic as possible model for a suspended gold nanowire under stress, we observe that the Au wire always breaks at an Au-Au bond, with a maximum bond length between 3.0 and 3.1 Å. Therefore, the experimentally observed large Au-Au bonds before the rupture of the nanowire (≈3.6 Å) are probably due to the presence of light impurities (X) forming Au-X-Au bonds. We obtain that the maximum Au-Au distance, for X equals C or N, is of the order of 3.9 Å, whereas for B and O it is of the order of 4.1 Å. On the other hand, for H this maximum distance before the rupture of the wire is approximately 3.6 Å, being the best candidate to explain the experimental results. For both C and H impurities, we present a detailed analysis of the neck atoms electronic structures, and compare them with similar results for the pure nanowire. © 2004 Elsevier B.V. All rights reserved.566-5681-3 PART 1367371Da Silva, E.Z., Da Silva, A.J.R., Fazzio, A., (2001) Phys. Rev. Lett., 87, p. 256102Ohnishi, H., Kondo, Y., Takayanagi, K., (1998) Nature, 395, p. 780Yanson, A.I., (1998) Nature, 395, p. 783Kondo, Y., Takayanagi, K., (2000) Science, 289, p. 606Tosatti, E., Prestipino, S., Kostlmeier, S., Dal Corso, A., Di Tolla, F.D., (2001) Science, 291, p. 288Rodrigues, V., Fuhrer, T., Ugarte, D., (2000) Phys. Rev. Lett., 85, p. 4124Rodrigues, V., Ugarte, D., (2001) Phys. Rev. B, 63, p. 073405Legoas, S.B., Galvão, D.S., Rodrigues, V., Ugarte, D., (2002) Phys. Rev. Lett., 88, p. 076105Torres, J.A., (1999) Surf. Sci. Lett., 83, p. 441Takai, Y., (2001) Phys. Rev. Lett., 87, p. 106105Bahn, S.R., (2002) Phys. Rev. B, 66, p. 081405Skorodumova, N.V., Simak, S.I., (2003) Phys. Rev. B, 67, p. 121404Novaes, F.D., Da Silva, A.J.R., Da Silva, E.Z., Fazzio, A., (2003) Phys. Rev. Lett., 90, p. 036101Ordejón, P., Artacho, E., Soler, J.M., (1996) Phys. Rev. B, 53, p. 10441Sáanchez-Portal, D., Ordejón, P., Artacho, E., Soler, J.M., (1997) Int. J. Quant. Chem., 65, p. 453Perdew, J.P., Burke, K., Ernzerhof, M., (1996) Phys. Rev. Lett., 77, p. 3865Troullier, N., Martins, J.L., (1991) Phys. Rev. B, 43, p. 1993Krüger, D., (2002) Phys. Rev. Lett., 89, p. 186402Rubio-Bollinger, G., (2001) Phys. Rev. Lett, 87, p. 26101