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　F-S　centers　(F-S(0),　F-S(+),　and　F-S(2+)).　Our　results　indicate　that　the　configuration　of　(WO3)(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　F-S(0)　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　(F-S(+)　and　F-S(2+)).　Accordingly,　three　F-S-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.　(C)　2013　American　Institute　of　Physics.　[http://dx.doi.org/10.1063/1.4776219]