χ² map of the inner radius R_in versus the inner surface density power-law p_in. For each value of these two parameters, the model with the lowest in the grid is included in the χ² map. The white dots indicate the models that were recomputed with a forsterite abundance of 1% included. The white diamond denotes the location of our base model. The black dot-dashed line shows the boundary between our original and the extended grid.