Conformational stability, vibrational spectral studies, HOMO-LUMO and NBO analyses of 2-hydroxy-4-methyl-3-nitropyridine and 2-hydroxy-4-methyl-5-nitropyridine based on density functional theory

► The harmonic vibrational wavenumbers of HM3NP and HM5NP have been carried out. ► Conformational stability and global minimum energies were found. ► Molecular electrostatic potential, HOMO and LUMO analysis have been performed. ► Mulliken's net charges have been calculated. ► NBO analysis determines the presence of hyperconjugative interactions another.