Configuration: b, however, exhibits evidence of tilting resembling the irrep 𝑋 3 + tilt mode and a trend akin to the experimental data. We observe that the degree of tilting increases as we traverse from the outer Ti atoms to the center Ti atoms. For instance, consider the five perovskite layers depicted in column 1 of arrangement (i) in SI Figure the outer BO6 octahedra is consistently smaller than that at the center BO6 octahedra, aligning with the observed tilting trends in the experimental data (refer to SI Table ). In Configuration: b, some of the outer and intermediate tilt angles are comparable to, if not greater than, those observed for the A2Bi4Ti5O18 m = 5 Aurivillius systems previously characterized by neutron diffraction, as illustrated in SI Table .