Local aspects of the As-stabilized 2x3 reconstructed (001) surface of strained InxGa1-xAs alloys: A first-principles study

Using the first-principles total-energy pseudopotential method, we study local aspects of an anion-terminated model of the (2 x 3) reconstructed (001) surface of strained InxGa1-xAs alloys. The structural model is based on recent in-plane x-ray-diffraction data [M. Sauvage-Simkin et at, Phys. Rev. Lett. 75, 3485 (1995)] and the in-plane coordinates of atoms are found in excellent agreement with the experiment. We demonstrate that values of some atomic coordinates are mainly due to strongly local features,such as arsenic dimerization and indium adaptation to the GaAs substrate. We finally discuss a way leading to some unknown quantities in this experiment, i.e., the atomic coordinates along the z axis.