What is an all-atom force field?
At the heart of molecular dynamics is a potential energy function, which describes the interatomic and intermolecular interactions. The first three terms are often refered to as the non-bonded interactions. The last three terms are called the bonded interactions, which model covalent bonds.
What is the difference between an all-atom forcefield and a united-atom forcefield?
All-atom force fields provide parameters for every type of atom in a system, including hydrogen, while united-atom interatomic potentials treat the hydrogen and carbon atoms in methyl groups and methylene bridges as one interaction center.
What is united-atom force field?
A united-atom is a particle that incorporates a group of atoms but can approximately represent the molecular mechanical properties of the group on a scale of size that is larger than atomic scale. It is also called psudo-atom.
What is an example of a force field?
A force field in physics is a map of a force over a particular area of space. This could be a map of the force the charges inside a compass needle feels, in which case we call it a magnetic field. Examples of force fields include magnetic fields, gravitational fields, and electrical fields.
Are all atom any better than united atom force fields for the description of liquid properties of alkanes?
In this study, the performance of 12 empirical force fields (FF) was evaluated in the context of reproducing liquid properties of alkanes. This overall better performance of the united-atom force fields indicates that complexity does not always bring quality.
What is force field in Gromacs?
A force field is built up from two distinct components: GROMACS 2021.3 includes several force fields, and additional ones are available on the website. If you do not know which one to select we recommend GROMOS-96 for united-atom setups and OPLS-AA/L for all-atom parameters.