A node structure (12, 14) for connecting two or more convergent members (16, 26) of a lattice frame to each other and to one or more other members of the lattice frame. The node structure (12, 14) comprises a pair of opposed spaced-apart faces (30) that are substantially planar and substantially parallel to each other. At least one pair of root formations (32) with respective central longitudinal axes define an interior angle between them, those axes diverging outwardly for alignment with respective members of the lattice frame and converging inwardly between the faces (30). An inner connecting wall (34) between the root formations (32) of the pair connects concave-curved inner edges (36) of the faces and extends in a concave curve around the interior angle to join the root formations (32) of that pair.