The　structure　and　composition　of　Au　nanostructures　deposited　on　TiO　x/Mo(112)　films　has　been　investigated　based　on　first　principles　DFT　calculations.　The　aim　of　the　calculations　is　to　identify　plausible　candidates　for　the　structures　generated　under　experimental　conditions　in　the　growth　of　Au/TiOx/Mo(112)　films.　To　this　end,　both　static　and　molecular　dynamics　(MD)　calculations　have　been　performed.　Various　Au　coverages　have　been　considered,　low　(below　monolayer),　medium　(monolayer),　and　high　(bilayer)　coverages.　An　ab　initio　thermodynamic　analysis　shows　that,　at　the　experimental　temperature　and　oxygen　partial　pressure,　the　Au　monolayer　forms　a　(1　×　1)　Au/TiO3/Mo(112)　structure.　On　the　basis　of　the　comparison　of　the　computed　and　experimental　valence　bands,　phonon　spectra,　and　STM　images,　we　propose　a　tentative　assignment　to　a　structure　where　Au　chains　are　formed　at　the　interface　between　the　Mo　support　and　the　TiO3　film.　The　additional　deposition　of　Au　results　in　the　formation　of　a　bilayer　(1　×　3)　Au/TiO　3/Mo(112)　structure.　Here,　we　observe　the　tendency　for　gold　to　aggregate　and　form　nanowires　with　half　of　the　Au　atoms　in　contact　with　the　TiO3/　Mo(112)　support　and　the　rest　forming　a　second　layer.　The　top　and　bottom　Au　layers　of　the　nanowire　exhibit　a　different　chemical　nature.　©　2008　American　Chemical　Society.