Cristallo e fiamma, due forme di bellezza perfetta da cui lo sguardo non sa staccarsi

Italo Calvino, Lezioni americane. Sei proposte per il prossimo millennio.

The successful reception of my previous posts on calculating the lattice energy, the calculation of the Born-Haber cycle and the Madelung constant motivated me to write more about the crystal structures of inorganic and organic compounds. In this series of articles, I will briefly introduce the crystallography. It does not pretend to be comprehensive, but it is meant to give just a flavor of this fascinating topic.

What is a Crystal?

At the atomic level, a crystal is solid with regular arrangements of atoms in space. Depending on the material, these arrangements have different symmetry properties that generate beautiful symmetric shapes at the macroscopic level.A regular and infinite arrangement of atoms can be visualized as a vast and complex network of interconnected particles. Each atom, with its unique properties, contributes to the overall complexity and variety of the system. The repeating patterns of the atoms create an endless and fascinating display. This assembly of atoms forms the basis of the world of matter, showcasing the intricate and beautiful nature of the smallest units of our universe.
We start introducing the Bravais lattice’s fundamental concept to describe and classify these atomic arrangements..The term “Bravais lattice” is a name given to a mathematical concept used to describe how points are arranged in a crystal. It is named after Auguste Bravais, a physicist from France who studied crystals in the 19th century. Bravais introduced the idea of different types of arrangements and symmetry in crystal structures. His work was important in understanding how crystals are classified based on their symmetry. The Bravais lattice is a fundamental concept in crystallography that describes the periodic arrangement of points in a crystal lattice. It provides a framework for classifying and categorizing different types of crystal structures based on their symmetry and arrangement of lattice points.

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