Intrinsic profiles beyond the capillary wave theory: a Monte Carlo study.

We develop and test an operational definition of the intrinsic surface for liquid-vapor interfaces. The application to the microscopic configurations along Monte Carlo computer simulations gives the statistical properties of the intrinsic surfaces and the intrinsic density profiles for simple fluid models. The results open a framework of quantitative description to close the gap between the mesoscopic capillary wave theory and the sharpest level of resolution for the intrinsic density distribution, relative to the first atomic layer in the liquid surface, as done in the interpretation of experimental x-ray reflectivity.