Molecular dynamics (MD) simulations are performed to study liquid oxygen in the temperature range from 84 to 120 K. The oxygen molecule is modeled as the Lennard-Jones diatomic carrying three point charges. This potential model is shown to reproduce the second virial coefficient in the temperatures range from 80 to 400 K and the heats of vaporization. The calculated structure factor for liquid oxygen is found to be in good agreement with neutron scattering data at 84 K. The orientational correlations in liquid oxygen are examined.