Vibrational and electronic absorption spectral studies of 5-amino-1-(4-bromophenyl)-3-phenyl-1-H-pyrazole

► The detailed vibrational assignments of 5-amino-1-(4-bromophenyl)-3-phenyl-1-H-pyrazole. ► The vibrational frequencies are calculated using density functional theory. ► NBO analysis is carried out for the title compound. ► The electronic absorption properties were explained and illustrated. ► The NLO and thermodynamic properties are calculated theoretically.