Molekylærmekaniske

Molekylærmekaniske, which translates to molecular mechanics in English, is a computational chemistry method used to model molecular systems. It relies on classical physics principles, specifically Newton's laws of motion, to describe the behavior of atoms and molecules. Instead of solving the Schrödinger equation like quantum mechanical methods, molecular mechanics treats atoms as spheres and chemical bonds as springs.

The core of molecular mechanics is the force field, a set of mathematical functions and parameters that describe the potential energy of a molecular system as a function of its atomic coordinates. These functions represent different types of interactions, including bond stretching, angle bending, torsional rotations, and non-bonded interactions such as van der Waals forces and electrostatic interactions. The parameters are typically derived from experimental data or higher-level quantum mechanical calculations.

By employing a force field, molecular mechanics can calculate the energy of a given molecular conformation and explore its conformational landscape. This allows for the prediction of stable structures, the study of reaction pathways, and the simulation of molecular dynamics over time. Molecular mechanics is computationally less demanding than quantum mechanical methods, making it suitable for studying large molecules like proteins and nucleic acids, as well as for simulating complex systems with many atoms. However, it cannot accurately describe phenomena that require an understanding of electronic structure, such as bond breaking and formation in detail or electronic transitions.