The equilibrium structure of monatomic steps on vicinal Si(001) is described in terms of anisotropic nearest-neighbor and isotropic second-nearest-neighbor interactions between dimers. By comparing scanning-tunneling-microscopy data and this equilibrium structure, we obtained interaction energies of 0.38 eV between dimers in a row, 0.24 eV between sets of two dimers in adjacent rows, and -0.07 eV for the diagonal interaction between dimers in adjacent rows.
Zandvliet, H. J. W., Elswijk, H. B., van Loenen, E. J., & Dijkkamp, D. (1992). "Equilibrium structure of monatomic steps on vicinal Si(001). Physical Review B (Condensed Matter), 0(45), 5965-5968. https://doi.org/10.1103/PhysRevB.45.5965