clicking the checkbox (121 state shown in Figure ). The orientation of the viewer can be adjusted through the mouse for optimal alignment and high-resolution images saved for use in student reports. This implementation complements existing didactic tools for visualizing PIB wavefunctions and energy levels. Notebook 2-PAHs with PySCF One natural source of skepticism on the part of students concerning the usefulness of the PIB model system is its seemingly contrived nature. Indeed, the impenetrability of the infinite potential on either side of the well that spatially confines the wavefunction is a mathematical construction. This concern is often addressed by noting that the trend of decreasing HOMO-LUMO gap with increasing box length (treating the electrons as non-interacting) qualitatively corresponds to the trend of decreasing optical excitation energy of linear polyenes. Concepts related to aromaticity like the 4n+2 rule can also emerge from the particle in a box/on a ring model. Another application of the 3D PIB system is to the orientation of the electrons in the 𝜋-orbital manifold of PAHs.