Introduction. 1. Complex Dielectric Tensor [IMG align=ABSMIDDLE alt=$\epsilon$]eps[/IMG]_ij(ω, k) and Normal Waves in the Medium. a) The Tensor [IMG align=ABSMIDDLE alt=$\epsilon$]eps[/IMG]_ij(ω, k) and Its Properties. b) Normal Electromagnetic Waves in a Medium. Transverse and Longitudinal Waves. "Fictitious" Longitudinal Waves and "Polarization Waves". c) Energy and Other Relations for Waves in an Anisotropic Medium. 2. The Tensor [IMG align=ABSMIDDLE alt=$\epsilon$]eps[/IMG]_ij(ω, k) in Crystals. a) The Concept of the Tensor [IMG align=ABSMIDDLE alt=$\epsilon$]eps[/IMG]_ij(ω, k) for Crystals 337. b) The Case of Weak Spatial Dispersion (a/λ ≪ 1). Cited Literature, Part I
3. Crystal optics with allowance for spatial dispersion 675
a) New wave near absorption line in gyrotropic crystals 676
b) New waves in non-gyrotropic crystals 679
c) Optical anisotropy of cubic crystals. Quadrupole absorption lines 681
d) Effect of mechanical stresses and external electric and magnetic fields 688
e) The problem of boundary conditions 694
f) Experimental investigations of effects of spatial dispersion in crystal optics 695
4. Quantum mechanical calculation of the tensor [IMG align=ABSMIDDLE alt=$\epsilon$]eps[/IMG]_ij(ω, k) 698
a) Quantum mechanical expression for [IMG align=ABSMIDDLE alt=$\epsilon$]eps[/IMG]_ij(ω, k) 698
b) Mechanical excitons and the tensor [IMG align=ABSMIDDLE alt=$\epsilon$]eps[/IMG]_ij(ω, k) in molecular crystals and in the case of the classical oscillator model 701
c) Absorption mechanism and calculations 705
Concluding remarks 706
Cited literature, part II.