The coexistence of gold-gold contacts and hydrogen bonding is studied in the model system [HP(OH)AuCl], and [H2P(OH)AuPH2(O)](2). The two interactions are found to be comparable. The possible non-additivity of the aurophilic, Au(I)-Au(I) interaction is studied at MP2 level for the pentagonal [Au(SH)(2)(AuSH)(5)](-) and hexagonal [Au(SH)(2)(AuSH)(6)](-) clusters. The possibilities of 'mechanical cooperativity' between different aurophilic attractions and of Au...S attractions are also considered. (C) 2003 Published by Elsevier Science B.V.