Contaminants in Suspended Gold Chains: AnAb InitioMolecular Dynamics Study

Recently, we have proposed that the origin of anomalously long interatomic distances in suspended gold chains could be the result of carbon contamination during sample manipulation [Phys. Rev. Lett. 88, 076105 (2002)]]. More recently, however, other works have proposed that hydrogen instead of carbon should be the most probable contaminant. We report ab initio molecular dynamics results for different temperatures considering different possible contaminants. Our results show that at nonzero temperatures (more realistic to simulate the experimental conditions) hydrogen may be ruled out and carbon atoms remain the best candidate for contamination.