The adsorption and reconstruction of strong electron acceptor tetracyanoethylene (TCNE) on Si(001)-(2 × 1): A density functional theory investigation

► TCNE molecule prefers to adsorb on the trench between adjacent two dimer rows. ► Abundant negative charge transfers from dimer Si to TCNE after adsorption. ► Strong interaction makes it difficult to diffuse for TCNE on Si(001). ► Charge transfer has effect on the STM images. ► Two surface reconstructions are predicted at different TCNE coverage.