Microscopic calculation of the optical properties of Si(100)2×1: Symmetric versus asymmetric dimers

A microscopic calculation of the optical properties of the Si(100)2×{}1 surface for both asymmetric and symmetric dimers is presented. The comparison with experiments allows us to discard a substantial presence of symmetric dimers from 40 to 310 K. An upper bound of 10% is obtained for their instantaneous population. Suggestions are made for future experiments.