Density functional theory calculations at the B3LYP level were performed on crystalline 2,4,6-trinitrochlorobenzene. The carbon, oxygen, and chlorine atoms make up the narrow lower energy bands, while the nitrogen, carbon, and oxygen atoms make up the higher energy bands. Besides, the contributions of these atomic orbitals to the frontier bands are somewhat well-proportioned. The Mulliken populations obviously demonstrate that the C-N bonds are the weakest, indicating that the C-NO2 is prone to rupture upon stimuli. An anisotropic impact on the bulk makes the electron transfer from chlorine to its neighbor carbon atom and from nitrogen atoms to oxygen atoms. The crystal lattice energy is predicted to be -50.99 kJ/mol, after being corrected for basis set superposition error.