I'm reading an article about the photo induced ligand loss of metal carbonyl complexes at the moment and heres a bit I'm having trouble getting my head around: Its the wavepacket part that I'm confused about. All I know is that a wavepacket is what you get when you combine multiple sine waves. I have no idea how this applies to an actual compound. Can anyone explain it in practical terms? When you shine light on the compound, the carbonyl ligands jump to higher energy states, similar to how electrons do. Where do wavepackets come into it?