Left, from top to bottom: the disk-center emergent Stokes profiles of the Si i 10 827 Å line for the granule model at the grid point ix = 28 and iy = 10 of the 3D snapshot model. Curves with different colors indicate the results for the three silicon model atoms (see Fig. 4). Thin solid line: LTE case. Right, from top to bottom: changes of the emergent Stokes parameters along the line profile caused by NLTE effects (thin solid curve) and by using the working atomic models instead of the simplest one. The NLTE effects are calculated by using the simplest working atomic model with six bb transitions. The dashed curve shows the results of comparing the NLTE profiles calculated by using the atomic models with six and 605 bb radiative transitions, while the green dashed-dotted curve shows the same for the atomic models with six and 4708 bb radiative transitions. S_H = 0.1.