Hückel π theory on each molecule's own adjacency matrix, contoured by
chython.depict.overlay.AtomField. Azulene HOMO–LUMO gap
0.878 |β|, naphthalene 1.236 |β|. Regenerate with
python docs/demo_qm/render_fields.py.
01_charge_azulene π charge on azulene — red electron-poor (seven-ring), blue electron-rich (five-ring). The dipole azulene is known for, as a field.02_charge_azulene_lines The same field as line contours (fill=False) at stated levels. The level at 0 is the charge-neutral curve, and the legend draws rules rather than blocks because no interval of values was filled.03_homo_naphthalene HOMO coefficients of naphthalene (RdBu). The two lobes meet along the nodal line through the fusion carbons, where the coefficient is exactly 0.04_homo_naphthalene_node The node drawn as a contour: level 0.0 on mono is mid-grey, so it is visible where the diverging map paints it the page colour. Four lobes of alternating sign, nodes along the fusion axis and across it.05_fukui_minus_azulene Azulene f⁻ (electrophilic attack, HOMO²), viridis, one-sided. Both panels carry the SAME domain 0–0.295, so the two are read against one scale — f⁻ peaks on the five-ring, f⁺ on the seven-ring.06_fukui_plus_azulene Azulene f⁺ (nucleophilic attack, LUMO²), viridis, one-sided. Both panels carry the SAME domain 0–0.295, so the two are read against one scale — f⁻ peaks on the five-ring, f⁺ on the seven-ring.07_polarizability_contoured Self-polarizability π_ii contoured — and this is the panel that should not be a contour. Range 0.330–0.443 |β|⁻¹: the interior is one flat colour and every band sits in the rim where the interpolation decays to zero.08_polarizability_halo The same numbers as AtomHalo(encode='both') — radius AND colour per atom. A scalar with no spatial structure is a per-atom quantity, and this form does not invent one. The α positions are the polarizable ones.09_clip_none clip=None — clip=None — the field's own cutoff closes it.10_clip_hull clip='hull' — hull, drawn through the atoms: bands are sliced.11_clip_box clip='box' — box over the label boxes.12_combined AtomField + Highlight + ValueLabels, with only the four extreme atoms numbered. The field is dropped to opacity 0.55 so the numbers stay legible on it; the numbers wear the ink colour, never the band colour.13_no_legend page.legend='none'. The bar is placed outside the content box, so withholding it moves no atom.