Dynamics near the surface reconstruction of W(100)

Using Brownian molecular dynamics simulation, we study the surface dynamics near the reconstruction transition of W(100) via a model Hamiltonian. Resu lts for the softening and broadening of the surface phonon spectrum near th e transition are compared with previous calculations and with He atom scatt ering data. From the critical behavior of the central peak in the dynamical structure factor, we also estimate the exponent of the power-law anomaly f or adatom diffusion near the transition temperature.