Comparison of Si VIII (or Si⁷⁺) effective collision strengths between the present work (M20), Tayal (2012, T12), Wang et al. (2018, W18), and Bell et al. (2001) as incorporated in the CHIANTI atomic database v9.0.1 (C-901) for selected transitions listed in Table 4. The top panel is a dipole transition from the ground level, followed by two metastable transitions. The bottom two panels are forbidden transitions from the ground level to the first two metastable levels. The vertical dashed lines indicate the upper temperature limit originally provided by Bell et al. (2001). The brown diamonds beyond this temperature limit are extrapolated in CHIANTI.