Can two T-shaped isomers of OCS-C2H2 van der Waals complex exist?

► DFT-D is used to investigate the properties of OCS-C2H2 vdW complex. ► Only one T-shaped isomer, OCS-C2H2 (S⊥) of the complex exists. ► Calculated molecular properties reproduce the experimental values. ► Interactions are studied by SAPT. ► Molecular properties are computed theoretically for the first time.