1：Experimental Design and Method Selection:

The study uses Raman spectroscopy, EXAFS, and M?ssbauer spectroscopy to analyze the structural changes in silicate glasses with varying sodium and fixed iron contents. The rationale is to understand the coordination and linkages in the glass network.

2：Sample Selection and Data Sources:

Glass samples were synthesized with compositions as per Table 1, using oxides from Thomas Baker (purity ≥99%). Samples were prepared by melting and quenching, and confirmed vitreous by X-ray diffraction.

3：List of Experimental Equipment and Materials:

Equipment includes a Carbolite 1600 furnace, agate pestle and mortar, platinum crucible, X-ray diffractometer (MoKα X-rays), field-emission scanning electron microscope (Quanta FEG 250, FEI, Netherlands) with EDAX (Smart Insight, USA), confocal micro spectrometer imaging spectroscope (STR 500, AIRIX Corp., Tokyo, Japan) with a 532 nm laser, EXAFS beam line (BL-09) at Indus-2 Synchrotron Source, and M?ssbauer spectrometer with WissEI velocity drive.

4：Experimental Procedures and Operational Workflow:

Samples were synthesized by weighing oxides, homogenizing, heating to 900°C for decomposition, then to 1400°C for melting, quenching in air, and annealing at 350°C. EDX was used for composition analysis, Raman spectroscopy for vibrational studies, EXAFS for local structure analysis, and M?ssbauer spectroscopy for iron state analysis.

5：Data Analysis Methods:

Raman spectra were deconvoluted using Gaussian curve fitting. EXAFS data were analyzed using IFEFFIT software (ATHENA and ARTEMIS) for fitting parameters. M?ssbauer spectra were fitted using NORMOS DIST/SITE software to obtain hyperfine parameters.