We　have　prepared　Eu3+　activated　phosphor　from　the　host　CaSc2O4　(CSO)　via　high-temperature　facial　solid-state　route　and　characterized　by　various　spectral　techniques.　Surface　morphology　and　composition　was　determined　via　scanning　electron　microscope　(SEM)　and　X-ray　energy　dispersive　spectroscopy　(EDAX).　The　crystal　structure　refinements　show　the　Pnam　62　space　group　with　two　active　centres　for　Eu3+　in　the　prepared　CSO:Eu3+　phosphor.　Additionally,　first　time　the　detailed　investigation　of　intermolecular　interactions　through　Hirshfeld　surface　(HSs)　analysis　for　the　inorganic　phosphor　has　been　reported,　the　analysis　indicates　that　the　Sc/Eu.O　and　Ca.O　contacts　in　the　CSO:Eu3+crystal　account　for　more　than　60%　and　26%　of　the　total　HSs　area.　The　synthesized　phosphor　shows　an　intense　red　emission　at　618　nm　(Ex　394　nm)　with　a　CIE　coordinates　of　(0.633,　0.358)　and　measured　internal　quantum　efficiency　(IQE)　was　found　to　be　84%.　Further,　correlated　colour　temperature　was　estimated　to　be　about　6049　K　including　colour　purity　of　93.04%　for　Eu　=　0.10　and　the　thermal　stability　were　established　by　their　temperature　dependent　study　(400　K　=　92%).　Therefore,　the　phosphor　of　CSO:Eu3+　exhibits　a　potential　application　for　UV-based　warm　white　LEDs　and　in　the　determination　of　intermolecular　interactions　through　HSs　surface　analysis　studies.　©　2020　John　Wiley　&　Sons　Ltd