Ionization-potential depressions of Si plasmas at the electron densities of 5.88 × 10²² cm⁻³ (black long-dashed-dotted line), 8.0 × 10²² cm⁻³ (black short-dashed-dotted line), 9.89 × 10²² cm⁻³ (black long-dashed line), 1.36 × 10²³ cm⁻³ (black short-dashed line), 1.7 × 10²³ cm⁻³ (black dotted line), 2.76 × 10²³ cm⁻³ (violet dashed-dashed-dotted line), 4.06 × 10²³ cm⁻³ (turquoise dashed-dotted-dotted line), 6.12 × 10²³ cm⁻³ (brown long-dashed-dotted line), 9.79 × 10²³ cm⁻³ (yello short-dashed-dotted line), 1.43 × 10²⁴ cm⁻³ (blue long-dashed line), 1.96 × 10²⁴ cm⁻³ (green short-dashed line), 2.57 × 10²⁴ cm⁻³ (red dotted line), and 3.25 × 10²⁴ cm⁻³ (black solid line). They are taken from the standard solar model (Bahcall & Ulrich 1988; Guenther et al. 1992).