Alpha plutonium is the room temperature allotrope of metallic plutonium. Its crystal structure has been determined by x-ray powder diffractometry. The structure is unusual in that regular bond lengths and angles do not occur. Contact distances between the plutonium atoms vary in length from 2.46 angstroms to 3.62 angstroms. One model of the 16 atoms in the unit cell, "PU_unit_cell_bonds.stl", shows the atoms as spheres connected by rods of various lengths. A second model of atoms in the unit cell, "PU_unit_cell_spheres.stl", shows the atoms as overlapping spheres. Another pair of models shows the contents of two unit cells.

Two atomic models are included which illustrate the irregular interatomic distances. "atom_8_spiked.stl" shows an atom with spikes whose length represent interatomic contacts; longer spikes represent more distant contacts. "atom_1_dimpled.stl" shows an atom with dimples, deeper dimples represent closer contacts.

OpenSCAD code is included; files at the end of the code list the interatomic distances. A fortran program was used to calculate coordinates and distances and is included.