Elektronelektronfrastøtning

Elektronelektronfrastøtning, often referred to in English as *electron-electron repulsion*, is a fundamental concept in atomic and molecular physics. It describes the electrostatic interaction between negatively charged electrons within an atom or molecule. Since electrons carry the same negative charge, they naturally repel one another due to Coulomb’s law, which governs the force between charged particles. This repulsion plays a critical role in determining the electronic structure and stability of atoms, influencing how electrons occupy orbitals and how molecules form.

In multi-electron systems, electron-electron repulsion counteracts the attractive force between electrons and the positively charged nucleus. This competition shapes the arrangement of electrons in atomic orbitals, leading to phenomena such as electron pairing in covalent bonds and the Aufbau principle, which dictates how electrons fill energy levels. The repulsion also contributes to the concept of electron correlation, where the motion of one electron affects the behavior of others, a key factor in quantum chemistry calculations.

In molecular systems, electron-electron repulsion helps explain bond angles and molecular geometries, as seen in VSEPR (Valence Shell Electron Pair Repulsion) theory. This theory predicts that electron pairs around a central atom arrange themselves to minimize repulsion, determining shapes like tetrahedral or trigonal planar structures. While electron-electron repulsion is inherently negative, it is essential for stabilizing molecular configurations and enabling chemical bonding.

Understanding electron-electron repulsion is crucial in fields such as spectroscopy, computational chemistry, and materials science, where precise modeling of electronic interactions is necessary for predicting molecular properties and reactions. Advanced methods, including Hartree-Fock theory and density functional theory, incorporate these repulsive forces to approximate electron behavior in complex systems.