STM studies of PTCDA supramolecular self-assembling on anisotropic surfaces of reconstructed InSb

► We apply room temperature STM to study the self-assembly of PTCDA molecules on InSb. ► We show a new approach comparing molecule behavior on different reconstructions. ► We use a new preparation procedure providing both reconstructions on the same sample. ► Molecules form well-ordered chains on the c(8 × 2) face and adsorb singly on the (1 × 3). ► The molecules form ordered structures on the c(8 × 2) surface and random on the (1 × 3).