Is the amount paid as compensation for a collision permissible, with the intention of donating it as charity?

As long as the person who caused the accident acknowledges it and has offered money as compensation for the damage, there is no harm in accepting it and using it for charity, repairing the damage, or other purposes. Compensation for damage is lawful and due to its owner, and "damage shall be removed," and "there shall be no harm or reciprocating harm."