The Force Field Energy

The force field energy is written as a sum of terms, each describing the energy required for distorting a molecule in a specific fashion. 

Given such an energy function of the nuclear coordinates, geometries and relative energies can be calculated by optimization. Stable molecules correspond to minima on the potential energy surface, and they can be located by minimizing Fff as a function of the nuclear coordinates. Conformational transitions can be described by locating 

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The force constants in the equations are adjusted empirically to repro duce experimental observations. The net result is a model which relates the "mechanical" forces within a stmcture to its properties. Force fields are made up of sets of equations each of which represents an element of the decomposition of the total energy of a system (not a quantum mechanical energy, but a classical mechanical one). The sum of the components is called the force field energy, or steric energy, which also routinely includes the electrostatic energy components. Typically, the steric energy is expressed as... 

Jorgensen WL, Maxwell DS, Tirado-Rives J (1996) J Am Chem Soc 118 11225 Jorgensen WL, McDonald NA (1998) Theochem - J Molec Struct 424 145 CAChe molecular moldelling program (1996) Oxford Molecular Group Inc In molecular mechanics the force field energy E is usually termed the steric energy of the molecule... 

We have alluded above that one measure of the accuracy of a force field can be its ability to predict heats of formation. A careful inspection of all of the formulas presented thus far, however, should make it clear that we have not yet established any kind of connection between the force-field energy and any kind of thermodynamic quantity. 

This methodology has two chief drawbacks. A philosophical drawback is that movement along the reaction coordinate raises the force-field energy instead of lowering it, which... 

Only the force-field energy term associated with interactions between the biotin and avidin fragments remains. This is added to the differential solvation free energies and differential thermal terms to determine the full binding free energy. 

The force field energy is written as a sum of terms, each describing-the energy required Tbrdistorting a molecule in a specific fashion.---------------------------------... 

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