We show that supersymmetric flux vacua with intermediate SU(2) structure is
closely related to some special classes of half-flat structures. More
concretely, solutions of the SUSY equations IIA possess a symplectic half-flat
structure, whereas solutions of the SUSY equations IIB admit a half-flat
structure which is in certain sense near to the balanced condition. Using this
result we show that compact simply connected manifolds do not admit type IIB
solutions. New solutions of the SUSY equations IIA and IIB are constructed from
hyperk\"ahler 4-manifolds, special hypo 5-manifolds and 6-dimensional
solvmanifolds.Comment: 21 pages; to be published in Classical Quantum Gravit
