Published theory of resonance absorption in crystals [L. N. Liebermann, Phys. Rev. 113, 1052 (1959)], while adequate for establishing the absorption mechanism, is not suitable for precise calculations. If the theory could be improved, acoustical absorption measurements could yield intermolecular force constants in solid crystals. Van der Waals forces in liquids and gases are known, but data on the solid state are practically nonexistent. One critical approximation in the present theory is the assumption that the Debye spectrum ρ(ν)=9Nν2/νm3 represents the actual vibrational modes of the lattice. Unfortunately the Debye maximum frequency νm occurs as νm7 in the present theory, thus making its numerical value extremely critical. Instead, solutions to the lattice vibrational modes can be given purely from vibrational constants of the lattice; for the cubical lattice, the vibrational modes resemble the acoustical modes of a rectangular room. The distribution function of the modes is considerably more complex than the Deybe function given above, but it is a function solely of the intermolecular force potential. Thus the critically uncertain Deybe parameter has been eliminated. Other improvements in the theory also are discussed.