Atom eigenfrequency in force field of nearest-neighbor atoms is the Debye frequency.•
Plasma frequency estimates the Debye frequency of ionic crystals and metal alloys.•
Reliability of calculated values of Debye temperature is characterized by R20.95R20.95.
A novel method is proposed to calculate the Debye frequency, speed of sound, and some other properties of ionic crystals and metal alloys from the plasma frequency of the ions. As an example of application, the theoretically obtained Debye temperatures TD of NaCl, KCl, RbI, AgBr, Cu3Au are 308 K, 238 K, 98 K, 149 K, and 296 K respectively, while an experiment gives 321 K, 235 K, 103 K, 140 K, and 285 K respectively. The reliability of calculated values of TD of the univalent and bivalent pure metals is characterized by R2≃0.985R2≃0.985. The hypothetical properties of solid under extremal conditions were estimated. For example, the metallic hydrogen has the theoretical determined TD≃4000