Reply to “Comment on ‘Impurity spectra of graphene under electric and magnetic fields' ”

In this reply to R. Van Pottelberge, M. Zarenia, and F. M. Peeters's comment on our original paper, ``Impurity spectra of graphene under electric and magnetic fields,'' we discuss the existence of bound states of a Coulomb impurity in graphene through the regular and irregular solution of the Dirac equation, and clarify its relation to the term ``atom collapse'' in our original paper.