Author/Authors :
da Silva Filho، نويسنده , , J.G. and Freire، نويسنده , , V.N. and Caetano، نويسنده , , E.W.S. and Ladeira، نويسنده , , L.O. and Fulco، نويسنده , , U.L. and Albuquerque، نويسنده , , E.L.، نويسنده ,
Abstract :
In this letter, we study the electronic structure and optical properties of the active medicinal component γ -aminobutyric acid (GABA) and its cocrystals with oxalic (OXA) and benzoic (BZA) acid by means of the density functional theory formalism. It is shown that the cocrystallization strongly weakens the zwitterionic character of the GABA molecule leading to striking differences among the electronic band structures and optical absorption spectra of the GABA crystal and GABA:OXA, GABA:BZA cocrystals, originating from distinct sets of hydrogen bonds. Calculated band widths and Δ -sol band gap estimates indicate that both GABA and GABA:OXA, GABA:BZA cocrystals are indirect gap insulators.
