Use $ams2026

Compare the HOMO-LUMO gap and frontier orbitals of ethylene with two ADF
settings.

Build ethylene from SMILES C=C. Optimize the geometry once with a modest ADF
GGA setup. Then run two ADF single-point calculations on the optimized
geometry: one with the same GGA setup and one with a hybrid functional.

For both single-point calculations, extract HOMO energy, LUMO energy, HOMO-LUMO
gap, and the energies of the nearest few occupied and virtual orbitals. Keep
units clear and report orbital energies in eV.

In the report, include a table comparing the two methods, and plot the frontier
orbital energy levels as a small energy-level diagram.

Include a picture of the optimized ethylene geometry. Include HOMO and LUMO
orbital isosurface pictures generated with amsreport.