We present a study of the pentaerythritol. tetranitrate energetic material by means of the ab initio all-electron periodic Hartree-Fock quantum mechanical method with the STO-3G basis set. Our calculations yield the equilibrium lattice vectors a(0) and c(0), the symmetry-preserving elastic constants (C-11 + C-12), C-33, and C-13, the bulk modulus B, and the linear moduli B. and B,. With regards to experiment, the average deviation of the calculated lattice vectors is 1% and that of the calculated elastic constants and moduli is 7.4%. In particular, the calculated bulk modulus 9.38 GPa agrees with experiment within 4.8%. Published by Elsevier B.V.