The breakdown of the direct relation between the density scaling exponent and the intermolecular interaction potential for molecular systems with purely repulsive intermolecular forces

•Contrary to theoretical consideration, intermolecular virial-potential-energy correlation does not provide the density scaling exponent for molecular systems.•Questioning generally accepted statement that character of intermolecular interactions can be directly determined from scaling exponent for real supercooled liquids.•Failure to determine the scaling exponent using the “molecular force” method suggests the scaling exponent depends on the intramolecular interactions. In this work, we question the generally accepted statement that the character of intermolecular interactions can be directly determined from the scaling exponent. We show that the scaling exponent evidently differs on the molecular architecture for pure inverse power law systems. Since these systems are characterized by a well-defined dependency between the intermolecular virial and potential energy, the results contradict theoretical predictions and previous reports. Moreover, we suggest that the recently proposed “molecular force” method also returns the value that varies from the one scaling the dynamics. Finally, the obtained result allows us to conclude that the value of the density scaling exponent for real liquids depends on intramolecular interactions.