S@Ag54 and I@Ag54 were crystallized in space groups of Fm-3 and Pa-3, respectively (Table ), and their geometric structures were determined using SC-XRD (Figures and). According to these geometric structures, the chemical compositions of S@Ag54 and I@Ag54 were X@Ag54S20(S t Bu)20(SO3 t Bu)m (X = S and I; S t Bu = tert-butanethiolate; SO3 t Bu = tert-butyl sulfonate) (hereafter, X@Ag54). Although the number of SO₃ t Bu ligands in both S@Ag54 and I@Ag54 was determined to be 12 by SCXRD, the latter cluster exhibits relatively high thermal parameters for the SO₃ t Bu ligands. We believe this is due to the lower occupancy of these ligands. Therefore, an attempt was made to estimate the number of SO3 t Bu ligands in I@Ag54 through 1 H NMR analysis.