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	Crystal field theory - Wikipedia, the free encyclopedia
		Crystal field theory was developed by the physicists Hans Bethe and John Hasbrouck van Vleck.
		In crystal field theory the metal ion is assumed to be free in gas form, the ligands are assumed to behave like point charges and it is assumed that the orbitals of the metal and the ligands do not interact.
		Crystal field theory describes how the ligands affect the d electrons and split them in to higher and lower (in terms of energy) groups - the energy difference between the two sets is given the symbol Δ.
	en.wikipedia.org /wiki/Crystal_field_theory (1067 words)

	Ligand field theory - Wikipedia, the free encyclopedia
		Ligand field theory was developed during the 1930s and 1940s as an expansion of the electrostatic crystal field theory, which offered a good description of the electronic structure of metal ions in coordination complexes but was not able to provide a proper explanation for their bonding.
		Like crystal field theory, ligand field theory is most easily understood by picturing ligands approaching a central metal ion and visualising the resulting orbital overlap.
		(O stands for octahedral) and is determined by strength of the interaction of the ligand orbitals with the d-orbitals on the central atom, as described in crystal field theory.
	en.wikipedia.org /wiki/Ligand_field_theory (1071 words)

	Crystal Field Theory
		This theory tried to describe the effect of the electrical field of neighboring ions on the energies of the valence orbitals of an ion in a crystal.
		As a result, the splitting observed in a tetrahedral crystal field is the opposite of the splitting in an octahedral complex.
		The splitting of d orbitals in the crystal field model not only depends on the geometry of the complex, it also depends on the nature of the metal ion, the charge on this ion, and the ligands that surround the metal.
	chemed.chem.purdue.edu /genchem/topicreview/bp/ch12/crystal.php (1278 words)

	Mineral Fluorescence: Crystal Field Theory cont'd (Site not responding. Last check: 2007-10-31)
		Crystal field theory suggests that the degenerate nature of the five d-orbitals for an isolated transition metal atom or ion will be altered when interacting with the anions composing the surrounding field.
		Crystal field splitting in tetrahedral coordination is smaller and opposite to that in octahedral coordination, ^t = (-4/9)^o.
		A property of transition metal ions, particularly sensitive to the effects of crystal field interactions, is the interatomic distance in a crystal structure.
	www.sas.upenn.edu /~reillyka/SpecProj/spec_theory2.html (721 words)

	An Introduction to Ligand and Crystal Field Theory
		Ligand and Crystal Field theories are used to describe the nature of the bonding in transition metal complexes.
		Crystal Field Theory is based upon the effect of a perturbation of the d-orbitals consisting of electronic interaction between the metal cation nucleus and the negatively charged electrons of the ligands: the metal-ligand interactions are electrostatic only.
		Ligand Field Theory treats the metal-ligand interaction as a covalent bonding interaction, and depends upon considering the overlap between the d-orbitals on the metals and the ligand donor orbitals.
	www.everyscience.com /Chemistry/Inorganic/Crystal_and_Ligand_Field_Theories/a.1012.php (455 words)

	BookRags: Ligand Field Theory Summary
		Crystal field theory cannot explain the covalent bonding that occurs in coordination complexes.
		The ligand field theory is especially useful for explaining the spectroscopic, magnetic, and optical characteristics of ions in the transition- metal and rare-earth groups.
		The ligand field theory's main concern is the effects of ligands on the energy levels of the central atom or ion.
	www.bookrags.com /research/ligand-field-theory-woc (537 words)

	Superposition Model Analyses
		Crystal field theory (CFT) has now met with widespread applications and successful interpretations of a wide range of physical and chemical properties of transition metal bearing minerals.
		In CFT the electronic structure of the central ion is taken into account, whereas the ligands are treated as point charges or point dipoles.
		The SM of crystal fields is based on the assumption that the crystal field can be expressed as the sum of axially symmetric contributions of all nearest neighbour ligands of the transition metal ion.
	www.univie.ac.at /Mineralogie/superpos.htm (1145 words)

	Carl J. Ballhausen : History of the Crystal Field Approach - Component of : Early Ideas in the History of Quantum ...
		demonstrated the superiority of the crystal field approach in the discussion of the magnetic properties of inorganic complexes.
		Thus the best features of both the valence-bond picture and the crystal field theory are incorporated in the ligand field theory, and it is this theory with which we shall be mostly concerned.
		Their very important papers directly confirmed the basic idea in the crystal field approach, namely, that the crystal field reduces the degeneracy of the electronic levels of the gaseous metal atom.
	www.quantum-chemistry-history.com /Ball_Dat/WhatsCFT.htm (1241 words)

	Crystal Field Theory
		With this theory, the bonding between the central metal atom and the ligands is completely ignored.
		Crystal Field Theory indeed becomes attractive when one has spectroscopy as a tool.
		The crystal field splitting is a measurable quantity.
	bouman.chem.georgetown.edu /S02/lect32/lect32.htm (626 words)

	Ligand-Field Theory (Site not responding. Last check: 2007-10-31)
		The valence-bond model and the crystal field theory explain some aspects of the chemistry of the transition metals, but neither model is good at predicting all of the properties of transition-metal complexes.
		A third model, based on molecular orbital theory, was therefore developed that is known as ligand-field theory.
		Ligand-field theory enables the 3d, 4s, and 4p orbitals on the metal to overlap with orbitals on the ligand to form the octahedral covalent bond skeleton that holds this complex together.
	chemed.chem.purdue.edu /genchem/topicreview/bp/ch12/ligand.php (283 words)

	Crystal Field Theory (CFT).
		To be able to understand and use CFT then, it is essential to have a clear picture of the shapes (angular dependence functions) of the d-orbitals.
		Jmol is an Open Source application for the display of molecular graphics that is capable of displaying atomic orbitals so it is possible to see the relationship between their orientation and ligands in different stereochemistries.
		One of the important aspects of CFT is that not all ligands are identical when it comes to causing a separation of the d-orbitals.
	wwwchem.uwimona.edu.jm /courses/CFT.html (1395 words)

	Crystal Field theory (Site not responding. Last check: 2007-10-31)
		Crystal field theory is a way of explaining the electronic structure and thus the color of complexes.
		These interactions cause the energies of electrons in these orbitals to split: this is the crystal field splitting energy, often abbreviated D. Electrons will enter the lower energy orbitals first.
		The magnitude of the splitting also determines the color of the complex.
	www.cartage.org.lb /en/themes/Sciences/Chemistry/Miscellenous/Helpfile/ComplexIons/CrystalFieldtheory/CrystalFieldtheory.htm (373 words)

	Crystal Field theory: spectrochemical series (Site not responding. Last check: 2007-10-31)
		Crystal field theory can be used to figure out the electron arrangement in a complex.
		The size of D is determined by the ligands that surround the metal ion.
		and Cl are weak field ligands: D is small in complexes with these ligands and these complexes tend to be high spin.
	www.cartage.org.lb /en/themes/Sciences/Chemistry/Miscellenous/Helpfile/ComplexIons/spectrochemicalseries/spectrochemicalseries.htm (209 words)

	Crystal Field Theory (Site not responding. Last check: 2007-10-31)
		In order to explore crystal field theory first one must become familiar with the orientation of available space which electrons can occupy.
		Because of this there are two resultant crystal shapes, octahedral and tetragonal.
		The energy drop when the electrons go back to the ground state plays a big role in what color we see and this is where spectroscopy comes in.
	www.sas.upenn.edu /~mhancock/Crystal_Field_Theory.html (333 words)

	McGraw-Hill AccessScience: Ligand field theory (Site not responding. Last check: 2007-10-31)
		Accordingly, the ligands are assumed to be sources of negative charge which perturb the energy levels of the central metal ion.
		In this respect the ligands subject the metal ion to an electric field which is analogous to the electric or crystal field produced by the regular distribution of nearest neighbors within an ionic crystalline lattice.
		The crystal field theory allows the energy levels to be calculated and related to experimental observation.
	www.accessscience.com /Encyclopedia/1/17/Est_171400_frameset.html (282 words)

	Mineralogical Applications of Crystal Field Theory - Cambridge University Press
		Crystal field theory provides a link between the visible region spectra and thermodynamic properties of numerous rock-forming minerals and gems that contain the elements iron, titanium, vanadium, chromium, manganese, cobalt, nickel or copper.
		Energy level diagrams and crystal field spectra of transition metal ions; 4.
		Crystal field spectra of transition metal ions in minerals; 6.
	www.cup.cam.ac.uk /catalogue/catalogue.asp?ISBN=0521017858 (293 words)

	crystal field theory definition - Dictionary - MSN Encarta
		crystal field theory definition - Dictionary - MSN Encarta
		Search for "crystal field theory" in all of MSN Encarta
		theory of properties of inorganic compounds: a theory that explains the properties of inorganic metal compounds in terms of a central metal atom surrounded by groups of atoms ligands that are electron-rich
	encarta.msn.com /encnet/features/dictionary/DictionaryResults.aspx?refid=561532991 (89 words)

	clayart - thread 'crystal field theory and quasicrystalline models' (Site not responding. Last check: 2007-10-31)
		due to the fact that both elements are known to exhibit high crystal field
		Zinc is a low field strength element however and dissolves
		readily in glaze, because it's ability to stay put in crystal form is weak.
	www.potters.org /subject30475.htm (407 words)

	CHEM2P32 Lecture 9: Crystal Field Theory
		Splitting of the d-Orbitals in an Octahedral Field
		All d-orbitals have the same energy (in spite of their different shapes and/or orientations) on a bare metal ion.
		Let's look at what happens to the energies of electrons in the d-orbitals as six ligands approach the bare metal ion:
	chemiris.labs.brocku.ca /~chemweb/courses/chem232/CHEM2P32_Lecture_9.html (513 words)

	Thermo Chromous Demo
		Explanations require Crystal field theory--although a bit strange, the essentials were covered in 2045C.
		The Co square planar complex also undergoes crystal field splitting but since lobes of dx
		Different ligands (anions) cause varying degrees of crystal field splitting.
	mooni.fccj.org /~ethall/cobalt/cobalt.htm (312 words)

	Crystal Field Theory: Theoretical Chemistry
		Crystal Field Theory (Eric Weisstein) - Text and Images.
		Crystal Field Theory (University of Bern) - Text and Images.
		Crystal Field Theory (University of Neuchatel) - Text and Images.
	www.infochembio.ethz.ch /links/en/theochem_kristallfeld.html (100 words)

	clayart - thread 'renaissance man, crystal field theory and quasicrystalline models' (Site not responding. Last check: 2007-10-31)
		clayart - thread 'renaissance man, crystal field theory and quasicrystalline models'
		renaissance man, crystal field theory and quasicrystalline models
		exist any more.--- crystal field theory and the quasicrystalline model>
	www.potters.org /subject30450.htm (102 words)

	Crystal Field Theory and Luminescence in Zinc Sulphide (Site not responding. Last check: 2007-10-31)
		Crystal Field Theory and Luminescence in Zinc Sulphide
		The luminescence of transition metal impurities in ZnS and related phosphors can in some instances be interpreted in terms of the crystal field splitting of a d
		In particular, reselling and systematic downloading of files is prohibited.
	stacks.iop.org /0370-1328/80/1385 (188 words)

	Crystal Field Theory
		Can anyone explain why, specifically in regards to Crystal Field Theory, why the lattice energies and Hydration enthalpies going across group 1 of the transition metals are not linear, except when considering only d0, d5, and d10 metals?
		I might be thinking of something entirely different - ionization energies or something...
		Posted: Sat May 21, 2005 10:27 pm Post subject: Re: Crystal Field Theory
	www.chemicool.com /forum/about46.html (224 words)

	Answers - Crystal Field Theory (Site not responding. Last check: 2007-10-31)
		Draw the M.O. diagram for an octahedral complex with six sigma donor ligands.
		Tetragonal distortions arising from a) different distances for the ligands, b) ligands of different field strength, and c) to remove degeneracy.
		Would the splitting pattern change if two of the Cu-O bond lengths were longer than the other four?
	www.cas.astate.edu /draganjac/cftanswers.html (253 words)

	Table of contents for Library of Congress control number 92037626 (Site not responding. Last check: 2007-10-31)
		Table of contents for Mineralogical applications of crystal field theory / Roger G. Burns.
		Bibliographic record and links to related information available from the Library of Congress catalog
		Library of Congress subject headings for this publication: Mineralogy, Crystal field theory
	www.loc.gov /catdir/toc/cam022/92037626.html (113 words)

	Closure procedures in crystal field theory (Site not responding. Last check: 2007-10-31)
		The group symmetry and unitary invariance of certain projection operators are discussed, and it is pointed out that closure approximations impose particular group symmetries on the intermediate states projection operators of second-order perturbation theory.
		The unitary invariance property of projection operators enables evaluation of second-order crystal field effects for a term without detailed knowledge of the crystal field levels of the perturbing terms.
		The latter result is applied in some numerical calculations for the rare earth Pr Print publication: Issue 1 (1 January 1970)
	stacks.iop.org /0022-3719/3/19 (216 words)

	Energy Citations Database (ECD) - Energy and Energy-Related Bibliographic Citations
		Energy Citations Database (ECD) Document #6011159 - Pairwise interaction method in crystal field theory
		Availability information may be found in the Availability, Publisher, Research Organization, Resource Relation and/or Author (affiliation information) fields and/or via the "Full-text Availability" link.
		For a journal article, please see the Resource Relation field.
	www.osti.gov /energycitations/product.biblio.jsp?osti_id=6011159 (121 words)

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