Heavier homonuclear diatomics (Li₂, N₂, O₂, F₂ …) build their molecular orbitals the same way H₂ does — by LCAO — but now from the 2s and 2p atomic orbitals. This tutorial shows the resulting orbital shapes and their symmetry labels (σ/π, gerade/ungerade, bonding/antibonding). Only the shapes are drawn — not the energies, which need many more integrals than the course computes. Each MO is the in-phase (bonding) or out-of-phase (antibonding) combination of one atomic orbital on each nucleus; blue is ψ>0, red is ψ<0. Drag to rotate.
Energies here are qualitative — the ordering, not the values. A computed σ/π energy diagram needs far more integrals than the course evaluates, so this is a schematic ladder, not a calculation. Bonding MOs (blue) sit below their parent AOs, antibonding (red) above. The σ2p ↔ π2p order flips between N₂ and O₂ (s–p mixing): π below σ for Li₂–N₂, σ below π for O₂–F₂. The orbital selected above is circled, linking its shape (below) to its place in the ladder.