Initial-state control in mutual neutralization of Si− with Na+ or K+ revealing strong violations of Wigner's spin-conservation rule

This repository contains all processed datasets required to reproduce the figures presented in a manuscript currently under review at Physical Review A. All data are provided in CSV format for ease of access and reuse, while the raw experimental data are available upon request from the corresponding author. The data used in Fig. 3 are contained in fig_3_values.csv, where the first column gives the storage time in seconds and the subsequent columns report neutral yields from laser photodetachment and residual gas collisions (the values shown in the figure correspond to the measured data divided by 10 for direct comparison). For the Na⁺ + Si⁻ system, Fig. 4 presents the final total centre-of-mass kinetic energy (Ek,f), with the corresponding data provided in fig_4_values.csv, including the final kinetic energy in eV and normalized counts for two datasets: ground + metastable states and pure ground state. Fig. 5 shows results for the same system, where the left panel displays the potential energy curve calculated for internuclear distances and the right panel presents the ΔEₖ spectrum obtained by subtracting an initial kinetic energy of (0.134 ± 0.020) eV from the measured final kinetic energy. For the K⁺ + Si⁻ system, Fig. 6 illustrates the final total centre-of-mass kinetic energy (Ek,f), with data provided in fig_6_values.csv, containing the final kinetic energy in eV and normalized counts for ground plus metastable and pure ground-state datasets. Figure 7 presents the corresponding potential energy curve and ΔEₖ spectrum for the K⁺ + Si⁻ system, where the PEC is calculated using the ionic potential expression over internuclear distances, and the ΔEₖ spectrum is obtained by subtracting an initial kinetic energy of (0.037 ± 0.014) eV from the measured final kinetic energy.In addition, the repository includes six text files: four files containing partial cross sections (in cm²) calculated using a semi-classical approach with ACAM and semi-empirical (Olson) coupling elements for both systems, considering cases with and without metastable-state contributions, and two additional files providing the interaction matrix elements H_i_j (in atomic units) used in the corresponding semi-classical treatments.