This image was generated using AVS, by Garrett M. Morris and Arthur J. Olson. It shows three conformations of the same inhibitor of HIV-1 protease. The atoms of this inhibitor are coloured by interaction energy: red atoms have positive energies, which implies unfavourable interaction, while blue atoms have negative energies and are therefore in favourable locations. The grid in the background shows the volume of space in which the inhibitor is allowed to explore during the docking. The white ''arrows'' and tubes form a so-called ribbon diagram, which depicts the secondary structure of HIV-1 protease.