While learning about carbon nanotubes I ran into the term molecular orbitals. I know something about atomic orbitals but took chemistry a long time ago. I would expect the concept of molecular orbitals to be useful for covalent bonding like Silicon crystals and metals. I would expect it's not useful for Ionic bonding (the electron is transfered and that's that) nor for bonding like Van Der Waals. Is this right? Since van der Waals bonding (like forces between liquid H2O molecules) don't involve electron sharing it's got nothing to do with molecular orbitals. Am I wrong? Thanks.