The Lewis formula refers to a diagram showing the distribution of electrones and in case of a molecule it also shows the bonds.
The structural formula on the other hand is a representation of the molecular structure that shows all the atoms that form the molecule, arranged in a three dimentional space,
In this case we have the hydrogen ion, which is the simpliest case we can have.
Hydrogen ion is the hydrogen atom possitively charged as it has lost his electron. Therefore the structural formula is simply the following:
The Lewis formula is also very simple as this ion has no electrons and has no bonding to other atoms:
