  A recipe is presented to construct an analytic, self-consistent model of a
non-barotropic neutron star with a poloidal-toroidal field of arbitrary
multipole order, whose toroidal component is confined in a torus around the
neutral curve inside the star, as in numerical simulations of twisted tori. The
recipe takes advantage of magnetic-field-aligned coordinates to ensure
continuity of the mass density at the surface of the torus. The density
perturbation and ellipticity of such a star are calculated in general and for
the special case of a mixed dipole-quadrupole field as a worked example. The
calculation generalises previous work restricted to dipolar, poloidal-toroidal
and multipolar, poloidal-only configurations. The results are applied, as an
example, to magnetars whose observations (e.g., spectral features and pulse
modulation) indicate that the internal magnetic fields may be at least one
order of magnitude stronger than the external fields, as inferred from their
spin downs, and are not purely dipolar.

High Energy Astrophysical Phenomena