Quantum chemical study on surface reconstruction of Si(100)

It is well known that Si atoms composing a Si(100) surface form a dimerized structure to stabilize the surface. This phenomenon is regarded as the Peierls instability that is generally found in polyacetylene. However, from the standpoint of the molecular orbital theory, there is few method to describe the Peierls instability efficiently for huge systems. We develop an efficient method to calculate the structural distortion on Si(100) surface and discuss the accuracy and efficiency of this method by comparing the result with the direct ab initio MO method.