The left most figure shows a Structurelab (sub)menu listing functions in this domain. The middle figure is the two-dimensional representation of a stem-loop structure. The right figure is the three-dimensional space filling model rendered by RasMol, calculated form the 2D via H. Martinez's rna_2d3d program for rough, preliminary 3D coordinates which can optionally utilize Amber for optimizations. The 3D structure shown is not optimized.