Use $ams2026

Optimize formaldehyde and calculate its vibrational frequencies with ADF.

Build formaldehyde from SMILES C=O and symmetrize. Run an ADF geometry
optimization with a modest GGA functional, a small-to-medium basis set,
and dispersion.

Verify that the optimized structure is a minimum with no imaginary
frequencies. Report the optimized C=O and C-H bond lengths and the H-C-H angle.

In the report, include a table of vibrational frequencies, IR intensities,
symmetries, and qualitative mode assignments. Plot a simple broadened IR
spectrum from the calculated frequencies and intensities.

For each normal mode, use plot_image_grid along_pca3 to show three pictures
side-by-side where you have displaced-in-negative-direction, optimized
structure, displaced-in-positive-direction.