Interaction energy

Interaction energy

In physics, interaction energy is the contribution to the total energy that is caused by an interaction between the objects being considered.

The interaction energy usually depends on the relative position of the objects. For example, Q_1 Q_2 / (4 pi epsilon_0 Delta r) is the electrostatic interaction energy between two objects with charges Q_1, Q_2.

Supermolecular interaction energy

A straightforward approach for evaluating the interaction energy is to calculate the difference between the energies of isolated objects and their assembly. In the case of two objects, "A" and "B", the interaction energy can be written as:

Delta E_{int} = E(A,B) - left( E(A) + E(B) ight),

where E(A) and E(B) are the energies of the isolated objects (monomers), and E(A,B) the energy of their interacting assembly (dimer).

For larger system, consisting of "N" objects, this procedure can be generalized to provide a total many-body interaction energy:

Delta E_{int} = E(A_{1}, A_{2}, .., A_{N}) - sum_{i=1}^{N} E(A_{i}).

By calculating the energies for monomers, dimers, trimers, etc., in an N-object system, a complete set of two-, three-, and up to N-body interaction energies can be derived.

The supermolecular approach has an important disadvantage in that the final interaction energy is usually much smaller than the total energies from which it is calculated, and therefore contains a much larger relative uncertainty.

See also

* Energy
* Force
* Interaction
* Perturbation theory (quantum mechanics)
* Potential


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • interaction energy — sąveikos energija statusas T sritis fizika atitikmenys: angl. interaction energy vok. Wechselwirkungsenergie, f rus. энергия взаимодействия, f pranc. énergie d’interaction, f …   Fizikos terminų žodynas

  • Energy level — A quantum mechanical system or particle that is bound that is, confined spatially can only take on certain discrete values of energy. This contrasts with classical particles, which can have any energy. These discrete values are called energy… …   Wikipedia

  • Energy-dispersive X-ray spectroscopy — (EDS, EDX or EDXRF) is an analytical technique used for the elemental analysis or chemical characterization of a sample. As a type of spectroscopy, it relies on the investigation of a sample through interactions between electromagnetic radiation… …   Wikipedia

  • Interaction d'echange — Interaction d échange En physique, l’interaction d échange est un effet quantique qui accroît ou décroît l énergie d un ou plusieurs électrons lorsque leurs fonctions d ondes se superposent. Conséquence du principe d exclusion de Pauli, cette… …   Wikipédia en Français

  • Energy minimization — (energy optimization) methods are common techniques to compute the equilibrium configuration of molecules. The basic idea is that a stable state of a molecular system should correspond to a local minimum of their potential energy. This kind of… …   Wikipedia

  • Energy transfer upconversion — or ETU is a physical principle (most commonly encountered in solid state laser physics) that involves the excitation of a laser active ion to a level above that which would be achieved by simple absorption of a pump photon, the required… …   Wikipedia

  • Energy — This article is about the scalar physical quantity. For other uses, see Energy (disambiguation). Energetic redirects here. For other uses, see Energetic (disambiguation) …   Wikipedia

  • Interaction d'échange — En physique, l’interaction d échange est un effet quantique qui accroît ou décroît l énergie d un ou plusieurs électrons lorsque leurs fonctions d ondes se superposent. Conséquence du principe d exclusion de Pauli, cette modification d énergie… …   Wikipédia en Français

  • Energy conservation — This article is about decreasing energy consumption. For the law of conservation of energy in physics, see Conservation of energy. Sustainable energy …   Wikipedia

  • Energy Information Administration — Infobox Government agency agency name = United States Energy Information Administration type = Agency nativename = nativename a = nativename r = logo = logo width = logo caption = seal width = 140px formed = October 1, 1977 dissolved =… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”