When particles are charged though, we instead solve for the electrostatic potential field and use that to determine the force on them. But in this case, are van der Waals forces still present? After all, van der Waals forces themselves are electrostatic phenomena - caused by induced dipole-dipole reactions between the two objects. Can I just add the van der Waals force to the electrostatic force, or is there a more subtle relationship between the two?