Muscimol hydration and vibrational spectroscopy – The impact of explicit and implicit water

•The theoretical structure of zwitterion tautomer of muscimol in water modelled explicitly and implicitly was determined.•An important role of water molecules in the first solvation shell was demonstrated.•The IR and Raman spectra of solid muscimol were observed for the first time.•Combined theoretical and experimental data support the presence of zwitterionic form of muscimol in solid state and water.