“…The excellent agreement between the calculated and experimental plasmon energy as a function of 8 in terms of R= 1.9 is additional convincing evidence that (SN)X is effectively an anisotropic threedimensional material. 112 Plasmon dispersion and optical properties of epitaxially grown (SN)X films have been studied by Stolz et al 113 By using a 30-keV electron beam, energy loss spectrum peaks for (SN)X at room temperature at 1.7, 2.4, 4.4, 6.2, 8.2, 12.0, and 22. surements on single crystals of (SN)X is about 1.5 eV. Plasmon energy values obtained by reflectivity are ca.…”