Understanding both the presence and implication of gap eigenvalues on the imaginary axis for solitary patterns in NLS is a challenging issue. The multi-scale nature of the problem considered comes from a separation of the localized 3D soliton from a small linear potential in the far field. Hamiltonian and geometric singular perturbation methods are combined to provide a count of the gap eigenvalues. A key part involves estimates on relevant Ricatti equations that arise naturally within a dynamical systems framework which brings out the multiscale structure. This is joint work with Emmanuel Fleurantin (GMU), Jeremy Marzuola and Dmitro Golovanich (UNC-CH)