Additionally, FP calculations using the conventional harmonic oscillator model and struc-tures optimized at 0 K were also performed on these surfaces, providing good comparison points for our results. Furthermore, these surfaces adopt a low-spin state, facilitating the convergence of FP calculations. Angular resolved X-ray photoemission spectroscopy conducted in the previous study revealed that Cu atoms are primarily located in the second layer from the surface. The amount of Cu in the second layer was controlled at 1/4 to 1 monolayer by varying the amount of deposited Cu atoms, while the other layers were mainly composed of Pt atoms. The models in Fig. (c) to (e) represent the observed Cu distribution in the second layer while the third layer of the symmetrical slab models used in the calculations does not fully represent the elemental distribution of the inner pure Pt layers in the experimental samples.