The natural population analysis (NPA), which calculated atomic charge and orbital population for 1 and 2 using Gaussian16 program package, shows a charge transfer from the ligands to the Pt ion and Ln ion, from the Pt atoms to Ln ion (Table . If it is a free ion, an atomic charge of Ln ion is +3). The natural atomic charges of La, Pt, CAc, S, O, (per atom), and the sum per Ph group in 1 are around +1.464 -0.187, +0.380, +0.011, -0.648, and -0.006, respectively. In addition, the natural atomic charges of the Gd, Pt, CAc, S, O, (per atom), and Ph group are around +1.544, -0.209, +0.419, +0.003, -0.684, and -0.002, respectively, in 2. The results of NBO and NPA is because the electron acceptability of Gd ion is lower than that of La ion (Details of the differences between Ln species are under investigation.). ). The peaks for 2 have been assigned based on the results of the TDDFT calculation. The absorption at around 4.20 eV in the experimental spectra is attributed to DMF. However, we omitted the DMF molecule in the calculations to reduce the calculation cost. The peak observed at around 3.32 eV was assigned to the transition from the Pt-S molecular orbital to the Gd-O molecular orbital, and the peak around 2.35 eV was assigned to the transitions from the Pt-S molecular orbital to the Gd molecular orbitals (Figure ). This Gd molecular orbital is an unoccupied orbital with 6s and 4f characters (s: 72.8%, p: 9.9% (mainly from the O atoms), d: 0.8%, f: 16.5%) (Figure ). The results of charge decomposition analysis (CDA) also indicated this hybridization ( orbital. Figure ). The absorption peaks in the range Local orbital locator. The LOL is a method used to evaluate the bond between two atoms. If the LOL function is a simple sum of the LOL functions of each atom, the bond between the atoms is ionic. If a new peak exceeding 0.5 is observed between the two atoms, the bond between these atoms is covalent. A dative bond (footnote: Although it is labeled as polar covalent bond in the references, it is labeled as dative bond according to the AIM classification below. 18b ) will appear as a shoulder peak or as a plateau below 0.5. The LOL results for 2 show the existence of a shoulder, indicating that the Pt center was strongly polarized by the Ln center (Figure ). These results may support the results of AIM. However, the LOL value ( = 0.2) is smaller than that obtained for the reported complexes (cf.  = 0.3); it means that the Gd-Pt bond in 2 is more ionic than that found for the reported complexes. 10b,10c Even perfect covalent bond, which has 50% covalency and 50% ionic.)" The contour plots on the Pt-Ln-Pt plane and the calculated value of  (electron density), and Etotal (total energy density)