Open shell

Open shell

In the context of atomic orbitals, an open shell is a valence shell which is not completely filled with electrons or that has not given all of its valence electrons through chemical bonds with other atoms or molecules during a chemical reaction. Atoms generally reach a noble gas configuration in a molecule. The noble gases (He, Ne, Ar, Kr, Xe, Rn) are not reactive and have configurations 1s2 (He), 1s22s22p6 (Ne), 1s22s22p63s23p6 (Ar), etc.

For molecules it signifies that there are unpaired electrons. In molecular orbital theory, this leads to molecular orbitals that are singly occupied. In computational chemistry implementations of molecular orbital theory, open shell molecules have to be handled by either the restricted Open-shell Hartree-Fock method or the unrestricted Hartree-Fock method.

Likewise a closed shell or closed shell configuration is obtained with a completely filled valence shell. This configuration is very stable.[1] In another meaning a closed shell configuration corresponds to state with all molecular orbitals doubly occupied or empty (a singlet state).[2] Open shell molecules are more difficult to study computationally[3]

See also

References


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать курсовую

Look at other dictionaries:

  • Restricted Open-shell Hartree-Fock — (ROHF) is a variant of Hartree Fock theory for open shell molecules. It uses doubly occupied molecular orbitals as far as possible and then singly occupied orbitals for the unpaired electrons. This is the simple picture for open shell molecules… …   Wikipedia

  • Shell Houston Open — Informations sur le tournoi Lieu Humble, Texas Fondation 1946 Parcours Redstone Golf Club Par 72 Longueur 7 457 yd …   Wikipédia en Français

  • Open Source Job Scheduler — Developer(s) Software und Organisations Service GmbH Stable release 1.3.7 / April 23, 2010; 18 months ago (2010 04 23) …   Wikipedia

  • Shell Centre — Shell Centre, in London, United Kingdom is one of the two central offices of oil major Shell (the other is in The Hague). It comprises a skyscraper tower and three nine storey wings (the upstream building ). It also once included a separate… …   Wikipedia

  • Open XML Paper Specification — (OpenXPS) Filename extension .oxps, .xps Internet media type application/oxps, application/vnd.ms xpsdocument Developed by Micro …   Wikipedia

  • shell — less, adj. shell like, adj. /shel/, n. 1. a hard outer covering of an animal, as the hard case of a mollusk, or either half of the case of a bivalve mollusk. 2. any of various objects resembling such a covering, as in shape or in being more or… …   Universalium

  • Open Firmware — Open Firmware, or OpenBoot in Sun Microsystems parlance, is a standard defining the interfaces of a computer firmware system, formerly endorsed by the Institute of Electrical and Electronics Engineers (IEEE). It originated at Sun, and has been… …   Wikipedia

  • Open the Door, Richard — is a song first recorded on the Black White Records label by saxophonistist Jack McVea at the suggestion of A R man Ralph Bass. In 1947, it was the number one song on Billboard s Honor Roll of Hits and became a runaway pop sensation.[1] Contents …   Wikipedia

  • Open Firmware — u OpenBoot, en la jerga de Sun Microsystems, es un estándar que define las interfaces de un sistema de firmware de computadora, anteriormente endosado por la IEEE. Fue originado en Sun, y ha sido usado por Sun, Apple, IBM, y la mayoría de los… …   Wikipedia Español

  • Shell Provider — sind Gruppen oder Unternehmen, die Shell Accounts von Unix, Linux, BSD oder anderen Betriebssystemen zur Verfügung stellen wo der Benutzer Anwendungen (wie zum Beispiel IRC Bots, IRC Server und andere) ausführen lassen kann oder den Account zur… …   Deutsch Wikipedia

Share the article and excerpts

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