By itself, these files won't do anything. An .esp would need to be used to distribute one-handed swords to Liches, at which point they would be able to equip and use them. If you so desired, the files could be renamed from their onehand prefix to twohand, to instead use 2H weapons...but it might look silly with how slender Lich arms are. This was released in my Auroran Prototype add-on for my More Creatures mod, but in a different directory, and with slightly modified vanilla animations. For more cool creature resources, check out:

More Creatures - Dragon Break Edition

These files were made using modified vanilla animations for other creatures, so all credit goes to Bethseda for this resource. Feel free to use them however you like.