Crystal structure determination, Hirshfeld surface, crystal void, inter­molecular inter­action energy analyses, as well as DFT and energy framework calculations of 2-(4-oxo-4,5-di­hydro-1H-pyra­zolo[3,4-d]pyrimidin-1-yl)acetic acid

In the title mol­ecule, C(7)H(6)N(4)O(3), the bicyclic ring system is planar with the carb­oxy­methyl group inclined by 81.05 (5)° to this plane. In the crystal, corrugated layers parallel to (010) are generated by N—H⋯O, O—H⋯N and C—H⋯O hydrogen-bonding inter­actions. The layers are associated through C—H⋯π(ring) inter­actions. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯O/O⋯H (34.8%), H⋯N/N⋯H (19.3%) and H⋯H (18.1%) inter­actions. The volume of the crystal voids and the percentage of free space were calculated to be 176.30 Å(3) and 10.94%, showing that there is no large cavity in the crystal packing. Computational methods revealed O—H⋯N, N—H⋯O and C—H⋯O hydrogen-bonding energies of 76.3, 55.2, 32.8 and 19.1 kJ mol(−1), respectively. Evaluations of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via dispersion energy contributions. Moreover, the optimized mol­ecular structure, using density functional theory (DFT) at the B3LYP/6–311G(d,p) level, was compared with the experimentally determined one. The HOMO–LUMO energy gap was determined and the mol­ecular electrostatic potential (MEP) surface was calculated at the B3LYP/6–31G level to predict sites for electrophilic and nucleophilic attacks.