The dark microwave conductivity (DMC) and time-resolved microwave conductivity (TRMC) data acquisition and analysis involve several steps, as discussed previously: 2-4 resonance curves are recorded for the empty cavity, the tube, and the sample to determine relative power reflection; TRMC transients are then collected at various laser intensities to confirm a linear response. A sensitivity factor (K) is subsequently applied to convert the raw data into yield-mobility products, with the transients fitted using a bi-exponential model adjusted for the cavity's response. The sample was enclosed in an EPR tube, sealed under vacuum in an argon atmosphere, with measurement errors in dark conductivity and dielectric constant primarily attributed to variations in tube geometry. The DMC revealed that (NH 3 (CH 2 ) 7 NH 3 ) 2 Sn 3 I 10 has a low relative dielectric constant of 2.47, followed by to Cs 2 SnI 6 (3.44), and (CH 3 NH 3 ) 2 SnI 6 (8.03), with frequencies of 9.72 GHz, 8.84 GHz, and 8.78 GHz, respectively (see Figure and Figure ). The loss of ionic sites in a material at higher frequencies has been reported to result in a relatively low dielectric constant. The decreasing trend in their frequencies aligns with the observed increase in their dielectric constant (see Table ). The measured yield-mobility product, derived from the transients measurements (see Figure ) exhibited that (NH 3 (CH 2 ) 7 NH 3 ) 2 Sn 3 I 10 exceeds that of (CH 3 NH 3 ) 2 SnI 6 but lower than that of Cs 2 SnI 6 . There is a solid excitation-wavelengthdependent photoconductivity in TRMC experiments, as summarized in Figure . scattering data were normalized, and sine Fourier transformed into the atomic pair distribution function using the software PDFgetX3. The PDFs were modeled using PDFgui. Equivalent data collected from nickel powder were used to extract the instrumental correc- Quantitative analysis of experimental PDFs obtained from Sn-based perovskites poses significant challenges to properly account for the anharmonic dynamics, which are nontrivial to accurately model. A key hallmark of this is the highly asymmetric peak corresponding Sn-I distances in the material (ca. 2.9-3.3 Å). Such asymmetry has even been observed in cubic, non-defective perovskites by us and by others. Curiously, the presence of different Sn-I bond lengths in [SnI 5 ] square pyramids overlaps with this anharmonic effect. Regardless, the observed Sn-I separations in this material are longer than the Sn-I distance expected for Sn(IV)-I bond lengths (2.84 Å, dashed green vertical line in Figure ) observed in A 2 SnI 6 compounds.