2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/81683We present linear response theories in the continuum capable of describing continuum spectra and dynamical correlations of finite systems with no spatial symmetry. Our formulation is essentially the same as the continuum random-phase approximation (RPA) but suitable for uniform grid representation in the three-dimensional (3D) Cartesian coordinate. Effects of the continuum are taken into account by solving equations iteratively with a retarded Green's function. The method is applied to photoabsorption spectra in small molecules (acetylene and ethylene) and inelastic electron scattering from a deformed nucleus 12C.Talk at RIKEN symposium on "Physics at Drip Lines", Wako, Japan, Feb. 13-16, 2001. 6 pages, 4 ps figuresNuclear Theorytext