Periodic　density　functional　theory　calculations　have　been　performed　to　study　the　most　stable　structure　of　the　(WO3)3　nanocluster　deposited　on　the　MgO(001)　surface　with　three　kinds　of　FS　centers　(FS0,　FS+,　and　FS　2+).　Our　results　indicate　that　the　configuration　of　(WO　3)3　cluster,　including　the　cyclic　conformation　and　the　heights　of　three　W　atoms,　and　the　oxidation　states　are　sensitive　to　the　charge　state　of　the　FS　center.　It　is　interesting　that　the　electron-riched　FS0　vacancy　on　the　MgO(001)　surface　can　act　as　a　promoting　site　to　enhance　the　W-W　interaction　and　the　W3O3　cyclic　conformation　is　maintained,　while　the　skeleton　of　cluster　becomes　flexible　when　(WO3)3　is　adsorbed　on　the　electron-deficient　vacancy　(FS+　and　FS2+).　Accordingly,　three　FS-centers　exhibit　different　arrangements　of　X-ray　photoelectron　spectra,　the　scanning　tunneling　microscopy　images,　and　the　vibrational　spectra　after　depositing　(WO3)3　cluster.　Present　results　reveal　that　the　(WO3)3　cluster　may　be　used　as　a　probe　to　identify　the　different　FS　centers　on　the　MgO(001)　surface.　©　2013　American　Institute　of　Physics.