Molekulafizika

Molekulafizika is a branch of physics that studies the physical properties and behavior of molecules and molecular systems. It aims to understand how the arrangement of atoms and the distribution of electrons determine molecular energy levels, bonding, spectra, and dynamics. The field lies at the intersection of quantum mechanics, statistical mechanics, and chemistry, and often uses theoretical and computational tools to predict and interpret molecular phenomena.

Key topics include electronic structure and chemical bonding, vibrational and rotational motion, intermolecular forces, and the dynamics of chemical reactions. The central framework is quantum mechanics, typically employing the Schrödinger equation and the Born-Oppenheimer approximation to separate electronic from nuclear motion and to produce potential-energy surfaces. Computational approaches range from ab initio methods and density functional theory to semi-empirical models and advanced quantum chemistry techniques, as well as molecular dynamics and path-integral simulations for studying finite-temperature effects.

Experimental aspects focus on spectroscopy and measurement of energy levels and transition probabilities. Infrared, Raman, microwave, and ultraviolet–visible spectroscopy reveal vibrational, rotational, electronic, and vibronic structure, while scattering and magnetic resonance techniques probe molecular interactions.

Applications span chemical physics, materials science, catalysis, atmospheric and astrochemistry, biophysics, and nanotechnology. The field has evolved from early quantum treatments of simple diatomic molecules to modern simulations that can model large biomolecules and condensed-phase systems. It provides fundamental insights into how matter behaves at the molecular scale and informs the design of new materials and technologies.