A quantum chemical computational insight into the intramolecular hydrogen bond interaction in an antibacterial drug molecule-2-acetylindan-1,3-dione

► Intramolecular H-bond interaction in a bio-active drug 2-acetylindan-1,3-dione has been investigated. ► The study emphasizes on quantum chemical assessment of H-bond interaction over geometry criteria. ► Topological and population analyses of the H-bond interaction have been explored quantum chemically. ► Partial covalency in the H-bond explained in the context of RAHB concept. ► The directional nature of H-bond is delineated under the NBO framework.