The ordered adsorption structures of FePc on Cu (1 0 0) have been studied by scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. With the deposition rate beyond 0.5 ML per min, the FePc molecules are not deposited dispersedly but are deposited as molecular clusters. After the heat treatment (the temperature higher than 420 K), the ordered organic structures of p(5 x 2) or p(2 x 5) are obtained. The ordered adsorption structures are in the tilt adsorption model. The FePc molecules in the different domains are aligned along the [0 1 1] or [01 (1) over bar] azimuth, respectively, the molecules are tilted. (C) 2010 Elsevier B. V. All rights reserved.