Data for: Structural, Electronic and Mechanical Properties of all-sp$^2$ Carbon Allotropes with Density Lower Than Graphene

Data report the stress-strain relationships for the materials proposed. Strain is reported in the first column (which must be multiplied by 2 to obtain the true strain). In the right column one may find the stress in Kbar. The cell in the direction orthogonal to the plane measures 20 Angstrom.