Solar spectrum of silicon and diagnostics of the solar atmosphere

We review published papers dealing with the formation of the silicon solar spectrum and its application for the diagnostics of the solar atmosphere. We pay particular attention to studies on determination of the solar abundance of silicon, its reliable estimation being required for solving the problem of solar metallicity. We analyze the effect of the errors of the oscillator strengths of spectral lines, damping constants, and rates of inelastic collisions with hydrogen atoms on the silicon abundance estimation errors. We also summarize the studies devoted to the investigation of the effect of the deviation from the local thermodynamic equilibrium, inhomogeneous structure of the solar atmosphere, and small-scale magnetic fields on the Si I line formation.