New concepts in the physics of solids

This work treats spectral and atomistic concepts derived from an analytical study of more than one hundred solids. The study deals with such characteristics as infrared spectra, specific heat, bulk-modulus, change of compressibility with pressure, lattice anharmonicity, exponent of repulsion, lattice cohesive energy, zero-point energy, hardness, and valence. Characterizing the lattice vibrations - that is, the infrared spectrum through one single frequency (the 'centro-frequency', defined by the center of gravity of the entire spectrum) - it is shown that an identical frequency may be derived as a mechanical analogy from the average velocity of sound determined, in this case, from the cubic compressibility. A thermodynamical analogy exists in the Debye frequency from specific heat. The 'centro-frequency' has proven to be the key to a successful formulation of the nonlinearity or anharmonicity of the attractive and repulsive forces in solids. The importance of anharmonicity for the understanding of the basic properties of solids from an atomistic point of view is shown through various applications. (Author).