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Resumen:
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This PhD was devoted to demonstrating that the nature and intrinsic features of a given pairwise interaction (covalent, electrostatic, van der Waals, etc.) defines a suitable framework to relate both molecular and bulk properties. To reach this goal, we have considered classical, well-established concepts from the field of condensed matter and translated them into the molecular realm, and vice versa. Pairwise interactions rest on the idea that the physical and chemical properties of a system can be accurately described considering only the potential energy curve between the neighbor atoms or, in other words, how the energy changes with the distance between the interacting particles. Several authors have demonstrated that the shape of the potential energy curve can be considered universal regardless that we consider a molecule or a crystal, implying that its general characteristics are also universally applicable and transferable from one system to the others. This procedure has been profusely applied in chemistry and physics of the solid state, but it has important the important limitation that to transfer the characteristic parameters it is required to fit specific experimental properties. In other words, the shape of the interaction potential is universal, but the characteristic parameters are not. Developing a methodology capable of providing truly universal parameters is one of the major challenges of this PhD thesis and one of its underlying motivations. . Commonly used potential functions include those classical of Lennard-Jones, Born-Mayer and Mie-Grüneisen, or others borrowed from spectroscopy, like Rydberg, Morse and Sutherland. And an example of the success of considering the universality of the potential energy curve was provided in the introduction chapter of this PhD memo with the model relating the stretching forcé constant of diatomic molecules with the bulk modulus of their ionic, metallic and covalent counterpart crystals. The key ideas to put forward such relationship were: to assume that the distance dependence of the diatomic stretching force constant can be universally described, and that they can accurately describe the interaction between the same atoms in the crystal. These two assumptions can be only fulfilled if the pairwise potential shape is universal and its parameters can be universally transferred between molecules and crystals...
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