Structure of the surface of liquid 4He at zero temperature

The ground-state wave function of a finite drop of liquid He⁴ is taken as a product of two-body and one-body factors. The surface energy is calculated, taking into account the variation of the two-particle-correlation function in the surface region, and is minimized by a density profile which falls off outside the liquid with a scale length 0.7 \AA{} and approaches the interior density with scale length 2 \AA{}. The calculated surface tension is 10% higher than the observed value.