Abstract
We start from the energy density of the Skyrme interaction and perform a leptodermous expansion for an asymmetric semiinfinite nuclear system. We get a liquid drop model formula for the energy of such a system. We use the obtained analytic formulae for volume, surface, and curvature energies to study the properties of asymmetric nuclear systems. We also study the effect of the asymmetry parameter on the volume, surface, and curvature properties.