Structural and dynamical properties of AsSe₄ liquids have been studied by ab initio molecular dynamics simulations as a function of temperature. Calculated neutron structure factors are in good agreement with experimental data. Results show the existence of a significant amount of AsAs homopolar bonds and of Se^I and As^IV units which are not part of the picture of the cross-linking As(Se_1 / 2)₃ pyramids usually proposed for the glassy state.