3D coordinate axes with polyhedra.
Rendering
\usepackage{polyhedra}
\begin{polyhedron}{dim=3, phi=60, theta=120} \axes{x={1,3}, y={1,3}, z={1,3}} \vertex{point={0,0,0}, text={O}} \edge{points={(0,0,0),(1.5,1,1)}} \end{polyhedron}
tikzorbital
p_z Orbital
polyhedra
2D Polygon