Crystal structure, Hirshfeld surface analysis and DFT study of 2,2′′-({[(1<i>E</i>,1′<i>E</i>)-(diselanediyl)bis(2,1-phenylene)]bis(methaneylylidene)}bis(azaneylylidene))bis[3′,6′-bis(diethylamino)-4a',9a'-dihydrospiro[isoindoline-1,9′-xanthen]-3-one]
Acta crystallographica. Section E, Crystallographic communications