toggle visibility
Search within Results:
Display Options:

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Nikolaev, A.V.; Lamoen, D.; Partoens, B. pdf  url
doi  openurl
  Title Extension of the basis set of linearized augmented plane wave (LAPW) method by using supplemented tight binding basis functions Type A1 Journal article
  Year (down) 2016 Publication The journal of chemical physics Abbreviated Journal J Chem Phys  
  Volume 145 Issue 145 Pages 014101  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract In order to increase the accuracy of the linearized augmented plane wave (LAPW) method, we present a new approach where the plane wave basis function is augmented by two different atomic radial components constructed at two different linearization energies corresponding to two different electron bands (or energy windows). We demonstrate that this case can be reduced to the standard treatment within the LAPW paradigm where the usual basis set is enriched by the basis functions of the tight binding type, which go to zero with zero derivative at the sphere boundary. We show that the task is closely related with the problem of extended core states which is currently solved by applying the LAPW method with local orbitals (LAPW+LO). In comparison with LAPW+LO, the number of supplemented basis functions in our approach is doubled, which opens up a new channel for the extension of the LAPW and LAPW+LO basis sets. The appearance of new supplemented basis functions absent in the LAPW+LO treatment is closely related with the existence of the ul-component in the canonical LAPW method. We discuss properties of additional tight binding basis functions and apply the extended basis set for computation of electron energy bands of lanthanum (face and body centered structures) and hexagonal close packed lattice of cadmium. We demonstrate that the new treatment gives lower total energies in comparison with both canonical LAPW and LAPW+LO, with the energy difference more pronounced for intermediate and poor LAPW basis sets.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000379584700003 Publication Date 2016-07-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9606 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.965 Times cited 11 Open Access  
  Notes A.V.N. acknowledges useful discussions with B. Verberck, E. V. Tkalya, and A. V. Bibikov. Approved Most recent IF: 2.965  
  Call Number c:irua:134290 Serial 4099  
Permanent link to this record
 

 
Author Tsvyashchenko, A.V.; Nikolaev, A.V.; Velichkov, A.I.; Salamatin, A.V.; Fomicheva, L.N.; Ryasny, G.K.; Sorokin, A.A.; Kochetov, O.I.; Budzynski, M.; Michel, K.H. doi  openurl
  Title Lowering of the spatial symmetry at the gamma ->alpha phase transition in cerium Type A1 Journal article
  Year (down) 2010 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 82 Issue 9 Pages 1-4  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using time-differential perturbed angular correlation spectroscopy we have measured the electric field gradient (EFG) at 111Cd probe nuclei in solid Ce in a pressure range up to 8 GPa. Covering various allotropic phases of Ce, we find that the value of the EFG in the cubic α phase is almost four times larger than in the cubic γ phase and close to values in the noncubic phases α′ and α″. These results together with the differences in time modulation of the spectra are interpreted as evidence for quadrupolar electronic charge-density ordering and symmetry lowering at the γ→α transition while the lattice remains face-centered cubic  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000282004400001 Publication Date 2010-09-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 11 Open Access  
  Notes ; This work is supported by the Program of the Presidium of the Russian Academy of Sciences “Physics of Strongly Compressed Matter.” We are grateful to S. M. Stishov, B. Verberck, A. N. Grum-Grzhimailo, V. B. Brudanin and G. Heger for support of this work and discussion of the results. ; Approved Most recent IF: 3.836; 2010 IF: 3.774  
  Call Number UA @ lucian @ c:irua:85464 Serial 1854  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Verberck, B.; Ionova, G.V. doi  openurl
  Title Molecular interaction energies and optimal configuration of a cubane dimer Type A1 Journal article
  Year (down) 2010 Publication International journal of quantum chemistry Abbreviated Journal Int J Quantum Chem  
  Volume 110 Issue 5 Pages 1063-1069  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We have studied the dependence of the binding energy of a cubane dimer on the mutual orientation of and the distance between the composing monomers employing the second-order Møller-Plesset perturbation scheme (MP2) with the cc-pVDZ molecular basis set. We have found that the MP2 contribution from the molecular correlations is responsible for the bound state of the cubane dimer, whereas the Hartree-Fock contribution remains anti-bonding at all intermolecular distances. Starting with two molecules in the standard orientation and centers of mass at (0,0,0) and (0,0,d), respectively, the maximal binding energy is found at d = 5.125 Å and one of the monomers rotated by 45° about the z-axis. This configuration implies that the hydrogen atoms belonging to different monomers tend to repel each other. The results are in agreement with experimental data on the optimal packing of cubane molecules in the solid state.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000274720000011 Publication Date 2009-04-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0020-7608;1097-461X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.92 Times cited 1 Open Access  
  Notes ; ; Approved Most recent IF: 2.92; 2010 IF: 1.302  
  Call Number UA @ lucian @ c:irua:81944 Serial 2179  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. doi  openurl
  Title Elusive s-f intrasite interactions and double exchange in solids: ferromagnetic versus nonmagnetic ground state Type A1 Journal article
  Year (down) 2009 Publication Journal of experimental and theoretical physics Abbreviated Journal J Exp Theor Phys+  
  Volume 109 Issue 2 Pages 286-292  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract From the theory of many-electron states in atoms, we know that there exists a strong Coulomb repulsion, which results in the electronic term structure of atoms and is responsible for Hunds rules. By expanding the Coulomb on-site repulsion into a multipolar series, we derive this interaction and show that it is also present in solids as a correlation effect, which means that the interaction requires a multideterminant version of the Hartree-Fock method. Of particular interest is the case where this interaction couples states of localized ( f) and delocalized ( s) electrons. We show that the interaction is bilinear in the creation/annihilation operators for localized electrons and bilinear in the operators for conduction electrons. To study the coupling, we consider a simple model in the framework of an effective limited configuration interaction method with one localized f-electron and one itinerant s-electron per crystal site. The on-site multipole interaction between the f- and s-electrons is explicitly taken into account. It is shown that depending on the low-lying excitation spectrum imposed by the crystal electric field, the model can lead not only to ferromagnetism but also to a nonmagnetic state. The model is relevant for solids with localized and itinerant electron states.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Woodbury, N.Y. Editor  
  Language Wos 000270506500014 Publication Date 2009-09-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1063-7761;1090-6509; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.196 Times cited 3 Open Access  
  Notes Approved Most recent IF: 1.196; 2009 IF: 0.871  
  Call Number UA @ lucian @ c:irua:79163 Serial 1027  
Permanent link to this record
 

 
Author Verberck, B.; Michel, K.H.; Nikolaev, A.V. doi  openurl
  Title The C60 molecules in (C60)N@SWCNT peapods: crystal field, intermolecular interactions and dynamics Type A1 Journal article
  Year (down) 2006 Publication Fullerenes, nanotubes, and carbon nanostructures Abbreviated Journal Fuller Nanotub Car N  
  Volume 14 Issue 2/3 Pages 171-178  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000238762900006 Publication Date 2006-06-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1536-383X;1536-4046; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.35 Times cited 10 Open Access  
  Notes Approved Most recent IF: 1.35; 2006 IF: 0.462  
  Call Number UA @ lucian @ c:irua:60025 Serial 3518  
Permanent link to this record
 

 
Author Michel, K.H.; Verberck, B.; Nikolaev, A.V. doi  openurl
  Title Nanotube field and one-dimensional fluctuations of C60 molecules in carbon nanotubes Type A1 Journal article
  Year (down) 2005 Publication European physical journal : B : condensed matter and complex systems Abbreviated Journal Eur Phys J B  
  Volume 48 Issue 1 Pages 113-124  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Berlin Editor  
  Language Wos 000233998600016 Publication Date 2005-12-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1434-6028;1434-6036; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.461 Times cited 25 Open Access  
  Notes Approved Most recent IF: 1.461; 2005 IF: 1.720  
  Call Number UA @ lucian @ c:irua:56408 Serial 2279  
Permanent link to this record
 

 
Author Michel, K.H.; Verberck, B.; Nikolaev, A.V. url  doi
openurl 
  Title Anisotropic packing and one-dimensional fluctuations of C60 molecules in carbon nanotubes Type A1 Journal article
  Year (down) 2005 Publication Physical review letters Abbreviated Journal Phys Rev Lett  
  Volume 95 Issue 18 Pages 185506-185506,4  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The confinement of a C-60 molecule encapsulated in a cylindrical nanotube depends on the tube radius. In small tubes with radius R-T less than or similar to 7 A, a fivefold axis of the molecule coincides with the tube axis. The interaction between C-60 molecules in the nanotube is then described by a O-2-rotor model on a 1D liquid chain with coupling between orientational and displacive correlations. This coupling leads to chain contraction. The structure factor of the 1D liquid is derived. In tubes with a larger radius the molecular centers of mass are displaced off the tube axis. The distinction of two groups of peapods with on- and off-axis molecules suggests an explanation of the apparent splitting of A(g) modes of C-60 in nanotubes measured by resonant Raman scattering.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000232887400041 Publication Date 2005-10-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.462 Times cited 40 Open Access  
  Notes Approved Most recent IF: 8.462; 2005 IF: 7.489  
  Call Number UA @ lucian @ c:irua:94717 Serial 127  
Permanent link to this record
 

 
Author Verberck, B.; Nikolaev, A.V.; Michel, K.H. pdf  doi
openurl 
  Title Orientational charge density waves and the metal-insulator transition in polymerized KC60 Type A1 Journal article
  Year (down) 2005 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 71 Issue 16 Pages 165117-11  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract A theoretical model is presented for the description of the metal-insulator transition which accompanies the structural phase transition at T approximate to 50 K in polymerized KC60. The model involves orientational charge density waves (along the C-60 polymer chains) which were introduced previously for a description of the structural phase transition. A satisfactory qualitative and quantitative understanding is obtained when the three-dimensionality of the crystal and the presence of the K+ counterions is properly taken into account.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000228763100035 Publication Date 2005-04-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1098-0121;1550-235X; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 1 Open Access  
  Notes Approved Most recent IF: 3.836; 2005 IF: 3.185  
  Call Number UA @ lucian @ c:irua:104076 Serial 2514  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. url  doi
openurl 
  Title Superexchange and electron correlations in alkali fullerides AC60, A=K, Rb, Cs Type A1 Journal article
  Year (down) 2005 Publication The journal of chemical physics Abbreviated Journal J Chem Phys  
  Volume 122 Issue 6 Pages 064310-64314  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Superexchange interactions in alkali fullerides AC(60) are derived for C-60 molecular ions separated by interstitial alkali-metal ions. We use a multiconfiguration approach which comprises the lowest molecular orbital states of the C-60 molecule and the excited s and d states of the alkali-metal atom A. Interactions are described by the valence bond (Heitler-London) method for a complex (C-60 – A – C-60) – with two valence electrons. The electronic charge transfer between the alkali-metal atom and a neighboring C-60 molecule is not complete. The occupation probability of excited d and s states of the alkali atom is not negligible. In correspondence with the relative positions of the C-60 molecules and A atoms in the polymer crystal, we consider 180degrees and 90degrees (angle) superexchange pathways. For the former case the ground state is found to be a spin singlet separated from a triplet at similar to20 K. For T < 20 K there appear strong spin correlations for the 180degrees superexchange pathway. The results are related to spin lattice relaxation experiments on CsC60 in the polymerized and in the quenched cubic phase. (C) 2005 American Institute of Physics.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000226918100018 Publication Date 2005-02-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9606; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.965 Times cited 11 Open Access  
  Notes Approved Most recent IF: 2.965; 2005 IF: 3.138  
  Call Number UA @ lucian @ c:irua:102740 Serial 3377  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. doi  openurl
  Title Ab initio approach to superexchange interactions in alkali doped fullerides AC60 Type P1 Proceeding
  Year (down) 2004 Publication AIP conference proceedings T2 – 18th International Winterschool/Euroconference on Electronic Properties, of Novel Materials, MAR 06-JUN 13, 2004, Kirchberg, AUSTRIA Abbreviated Journal  
  Volume Issue Pages 393-396  
  Keywords P1 Proceeding; Condensed Matter Theory (CMT)  
  Abstract The superexchange interactions between the fullerenes arise as a result of the electron transfer from the C-60 molecule to the alkali atom and back. We present a scheme, which is a configuration interaction approach based on the valence bond (Heitler-London) method. The effect of superexchange is described together with chemical bonding by constructing and solving a secular equation, rather than by using a perturbation treatment. We have considered 180degrees and 90degrees superexchange for the C-60 Cs-C-60 pathways. The calculations account for unusual electronic properties of polymer orthorhombic and quenched cubic phases of CsC60: two lines in nuclear magnetic resonance experiments, the development of a spin-singlet ground state and a decrease of magnetic susceptibility as T-->0.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York Editor  
  Language Wos 000224699400085 Publication Date 2004-11-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 723 Series Issue Edition  
  ISSN 0-7354-0204-3 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:103752 Serial 27  
Permanent link to this record
 

 
Author Verberck, B.; Popov, V.N.; Nikolaev, A.V.; Lamoen, D. doi  openurl
  Title Valence electronic charge density of distorted C60-monomers in polymerized KC60 and RbC60 Type A1 Journal article
  Year (down) 2004 Publication The journal of chemical physics Abbreviated Journal J Chem Phys  
  Volume 121 Issue Pages 321  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000222112100035 Publication Date 2004-06-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9606; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.965 Times cited 7 Open Access  
  Notes Approved Most recent IF: 2.965; 2004 IF: 3.105  
  Call Number UA @ lucian @ c:irua:47380 Serial 3830  
Permanent link to this record
 

 
Author Verberck, B.; Nikolaev, A.V.; Michel, K.H. doi  openurl
  Title Theoretical model for the structural phase transition and the metal-insulator transition in polymerized KC60 Type A1 Journal article
  Year (down) 2004 Publication Fullerenes, nanotubes, and carbon nanostructures T2 – 6th Biennial International Workshop on Fullerenes and Atomic Clusters, JUN 30-JUL 04, 2003, St Petersburg, RUSSIA Abbreviated Journal Fuller Nanotub Car N  
  Volume 12 Issue 1-2 Pages 243-252  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract The recently discovered structural phase transition in Polymerized KC60 at about 50K leads to a doubling of the unit cell volume and is accompanied by a metal-insulator transition. Here, we show that the ((a) over right arrow + (c) over right arrow, (b) over right arrow, (a) over right arrow – (c) over right arrow) superstructure results from orientational charge density waves along the polymer chains and correlated displacements of the K+ ions. The presented model can also account for the metal-insulator transition. The effect is specific for the space group Pmnn of KC60 and is absent in both Rb- and CsC60 (space group 12/m), in agreement with the present experimental knowledge of these compounds.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000220551600040 Publication Date 2004-03-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1536-383X;1536-4046; ISBN Additional Links UA library record; WoS full record  
  Impact Factor 1.35 Times cited Open Access  
  Notes Approved Most recent IF: 1.35; 2004 IF: 1.117  
  Call Number UA @ lucian @ c:irua:103259 Serial 3607  
Permanent link to this record
 

 
Author Verberck, B.; Nikolaev, A.V.; Michel, K.H. openurl 
  Title Orientational charge density waves and the metal-insulator transition in polymerized KC60 Type A1 Journal article
  Year (down) 2004 Publication AIP conference proceedings Abbreviated Journal  
  Volume 723 Issue Pages 339-342  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Polymerized KC60 undergoes a structural phase transition accompanied by a metal-insulator transition around 50 K. To explain the structural aspect, a mechanism involving small orientational deviations of the valence electron density on every C-60 monomer orientational charge density waves (OCDWs) – has already been proposed earlier. In the present work, we address the metal-insulator transition using the OCDW concept. We are inspired by the analogy between a polymer chain exhibiting an OCDW and a linear atomic chain undergoing a static lattice deformation doubling the unit cell: such a deformation implies a band gap at the zone boundary, yielding an insulating state (Peierls instability). Within our view, a similar mechanism occurs in polymerized KC60; the OCDW plays the role of the lattice deformation. We present tight-binding band structure calculations and conclude that the metal-insulator transition can indeed be explained using OCDWs, but that the threedimensionality of the crystal plays an unexpected key role.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0094-243x ISBN Additional Links UA library record; WoS full record;  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:94831 Serial 2513  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. doi  openurl
  Title Many electron- and hole terms of molecular ions C60n\pm Type A1 Journal article
  Year (down) 2003 Publication Coupling In Chemistry And Physics Abbreviated Journal Adv Quantum Chem  
  Volume 44 Issue Pages 305-312  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000188940800019 Publication Date 2004-05-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0065-3276; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.196 Times cited 1 Open Access  
  Notes Approved Most recent IF: 1.196; 2003 IF: 0.375  
  Call Number UA @ lucian @ c:irua:104131 Serial 1942  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. url  doi
openurl 
  Title Symmetry lowering at the structural phase transitions in NpO2 and UO2 Type A1 Journal article
  Year (down) 2003 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 68 Issue 5 Pages 054112-054112,7  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The structural phase transitions with electric-quadrupole long-range order in NpO2 (Fm (3) over barm-->Pn (3) over barm) and UO2 (Fm (3) over barm-->Pa (3) over bar) are analyzed from a group theoretical point of view. In both cases, the symmetry lowering involves three quadrupolar components belonging to the irreducible representation T-2g (Gamma(5)) of O-h and condensing in a triple-q structure at the X point of the Brillouin zone. The Pa (3) over bar structure is close to Pn (3) over barm, but allows for oxygen displacements. The Pa (3) over bar ordering leads to an effective electrostatic attraction between electronic quadrupoles while the Pn (3) over barm ordering results in a repulsion between them. It is concluded that the Pn (3) over barm structure can be stabilized only through some additional process such as strengthening of the chemical bonding between Np and O. We also derive the relevant structure-factor amplitudes for Pn (3) over barm and Pa (3) over bar, and the effect of domains on resonant x-ray scattering experiments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000185240100038 Publication Date 2003-08-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 15 Open Access  
  Notes Approved Most recent IF: 3.836; 2003 IF: NA  
  Call Number UA @ lucian @ c:irua:94847 Serial 3405  
Permanent link to this record
 

 
Author Verberck, B.; Nikolaev, A.V.; Michel, K.H. url  doi
openurl 
  Title Theoretical model for the structural phase transition at the metal-insulator transition in polymerized KC60 Type A1 Journal article
  Year (down) 2002 Publication Physical Review B Abbreviated Journal Phys Rev B  
  Volume 66 Issue 16 Pages 165425-165425,14  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The recently discovered structural transition in polymerized KC60 at about 50 K results in a doubling of the unit cell volume and accompanies the metal-insulator transition. Here we show that the ((a) over right arrow+(c) over right arrow,(b) over right arrow,(a) over right arrow-(c) over right arrow) superstructure results from small orientational charge density waves along the polymer chains and concomitant displacements of the surrounding K+ ions. The effect is specific for the space group Pmnn of KC60 and is absent in RbC60 and CsC60 (space group I2/m). The mechanism is relevant for the metal-insulator transition.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000179286400135 Publication Date 2002-10-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 10 Open Access  
  Notes Approved Most recent IF: 3.836; 2002 IF: NA  
  Call Number UA @ lucian @ c:irua:94907 Serial 3608  
Permanent link to this record
 

 
Author Verberck, B.; Michel, K.H.; Nikolaev, A.V. pdf  doi
openurl 
  Title Crystal structures of polymerized fullerides AC60, A=K, Rb, Cs, and alkali-mediated interactions Type A1 Journal article
  Year (down) 2002 Publication The journal of chemical physics Abbreviated Journal J Chem Phys  
  Volume 116 Issue 23 Pages 10462-10474  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Starting from a model of rigid interacting C-60 polymer chains on an orthorhombic lattice, we study the mutual orientation of the chains and the stability of the crystalline structures Pmnn and I2/m. We take into account (i) van der Waals interactions and electric quadrupole interactions between C-60 monomers on different chains as well as (ii) interactions of the monomers with the surrounding alkali atoms. The direct interactions (i) always lead to an antiferrorotational structure Pmnn with alternate orientation of the C-60 chains in planes (001). The interactions (ii) with the alkalis consist of two parts: translation-rotation (TR) coupling where the orientations of the chains interact with displacements of the alkalis, and quadrupolar electronic polarizability (ep) coupling, where the electric quadrupoles on the C-60 monomers interact with induced quadrupoles due to excited electronic d-states of the alkalis. Both interactions (ii) lead to an effective orientation-orientation interaction between the C-60 chains and always favor the ferrorotational structure I2/m, where C-60 chains have a same orientation. The structures Pmnn for KC60 and I2/m for Rb- and CsC60 are the result of a competition between the direct interaction (i) and the alkali-mediated interactions (ii). In Rb- and CsC60 the latter are found to be dominant, the preponderant role being played by the quadrupolar electronic polarizability of the alkali ions. (C) 2002 American Institute of Physics.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000175905800044 Publication Date 2002-07-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9606; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.965 Times cited 12 Open Access  
  Notes Approved Most recent IF: 2.965; 2002 IF: 2.998  
  Call Number UA @ lucian @ c:irua:103350 Serial 578  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. openurl 
  Title Molecular terms and optical transitions of C60n+/- molecular ions Type P1 Proceeding
  Year (down) 2002 Publication AIP conference proceedings T2 – 16th International Winterschool on Electronic Properties of Novel, Materials, MAR 02-09, 2002, KIRCHBERG, AUSTRIA Abbreviated Journal  
  Volume Issue Pages 417-420  
  Keywords P1 Proceeding; Condensed Matter Theory (CMT)  
  Abstract We have studied the molecular energy terms of the hole configurations (h(u)(+))(m), m=2,3,4,5 of C-60(m+) cations and the electronic configurations (t(1u))(n) n=2,3,4, as well as (t(1u))(n-1)t(1g) of the C-60(n-) anions. The lowest terms (within an energy span of 0.03 eV) for C-60(2+) are three triplets T-3(1g), (3)G(g), T-3(2g) and for C-60(3+) are three quartets T-4(1u), (4)G(u), T-4(2u), which favor Jahn-Teller distortions. For the ground state of C-60(2-) we find a triplet T-3(1g) in agreement with Hund's rules. Our method takes into account intramolecular direct and exchange multipolar Coulomb interactions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 633 Series Issue Edition  
  ISSN 0-7354-0088-1 ISBN Additional Links UA library record; WoS full record;  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:103905 Serial 2187  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. doi  openurl
  Title Microscopic theory of quadrupolar oredring in TmTe Type A1 Journal article
  Year (down) 2001 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 63 Issue Pages 1-10  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos 000167402100025 Publication Date 2002-07-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 7 Open Access  
  Notes Approved Most recent IF: 3.836; 2001 IF: NA  
  Call Number UA @ lucian @ c:irua:36882 Serial 2033  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. doi  openurl
  Title Electronic structure and electric quadrupoles of a polymerized chain in solid AC60 Type A1 Journal article
  Year (down) 2001 Publication Solid state communications Abbreviated Journal Solid State Commun  
  Volume 117 Issue Pages 739-743  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000167538300010 Publication Date 2002-07-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0038-1098; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.554 Times cited 10 Open Access  
  Notes Approved Most recent IF: 1.554; 2001 IF: 1.381  
  Call Number UA @ lucian @ c:irua:36881 Serial 1009  
Permanent link to this record
 

 
Author Michel, K.H.; Nikolaev, A.V.; Verberck, B. openurl 
  Title Theory of crystal structures of polymerized C60-fullerite and fullerides AC60, A=K, Rb, Cs Type H1 Book chapter
  Year (down) 2001 Publication Abbreviated Journal  
  Volume Issue Pages  
  Keywords H1 Book chapter; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication s.l. Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 462-465 Series Issue Edition  
  ISSN ISBN Additional Links UA library record; WoS full record;  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:36883 Serial 3614  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. doi  openurl
  Title Electric quadrupole interactions and the γ-α phase transition in Ce: the role of conduction electrons Type A1 Journal article
  Year (down) 2000 Publication European physical journal : B : condensed matter and complex systems Abbreviated Journal Eur Phys J B  
  Volume 17 Issue Pages 15-32  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Berlin Editor  
  Language Wos 000089339900004 Publication Date 2003-05-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1434-6028; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.461 Times cited 8 Open Access  
  Notes Approved Most recent IF: 1.461; 2000 IF: 2.077  
  Call Number UA @ lucian @ c:irua:34338 Serial 888  
Permanent link to this record
 

 
Author Michel, K.H.; Nikolaev, A.V. url  doi
openurl 
  Title Theory of distinct crystal structures of polymerized fullerides AC60, A=K, Rb, Cs: the specific role of alkalis Type A1 Journal article
  Year (down) 2000 Publication Physical review letters Abbreviated Journal Phys Rev Lett  
  Volume 85 Issue Pages 3197-3200  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000089807800033 Publication Date 2002-07-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007;1079-7114; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.462 Times cited 16 Open Access  
  Notes Approved Most recent IF: 8.462; 2000 IF: 6.462  
  Call Number UA @ lucian @ c:irua:34339 Serial 3615  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. doi  openurl
  Title Quantum charge density fluctuations and the γ-α phase transition in Ce Type A1 Journal article
  Year (down) 1999 Publication European physical journal : B : condensed matter and complex systems Abbreviated Journal Eur Phys J B  
  Volume 9 Issue Pages 619-634  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Berlin Editor  
  Language Wos 000081615500009 Publication Date 2002-08-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1434-6028; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.461 Times cited 19 Open Access  
  Notes Approved Most recent IF: 1.461; 1999 IF: 1.705  
  Call Number UA @ lucian @ c:irua:28504 Serial 2774  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H.; Copley, J.R.D. openurl 
  Title Orientational disorder and order in C60-fullerite and in MC60-alkali metal fullerides Type H3 Book chapter
  Year (down) 1999 Publication Abbreviated Journal  
  Volume Issue Pages 183-214  
  Keywords H3 Book chapter; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Plenum Press Place of Publication New York Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:28505 Serial 2515  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Prassides, K.; Michel, K.H. doi  openurl
  Title Charge transfer and polymer phases in AC60 (A=K, Rb, Cs) fullerides Type A1 Journal article
  Year (down) 1998 Publication The journal of chemical physics Abbreviated Journal J Chem Phys  
  Volume 108 Issue Pages 4912-4923  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000072588400025 Publication Date 2002-07-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9606; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.965 Times cited 14 Open Access  
  Notes Approved Most recent IF: 2.965; 1998 IF: 3.147  
  Call Number UA @ lucian @ c:irua:23985 Serial 338  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Prassides, K.; Michel, K.H. openurl 
  Title Phase transitions in AC60 (A=Rb, Cs) fullerides Type A3 Journal article
  Year (down) 1997 Publication Recent advances in the chemistry and physics of fullerenes and related materials Abbreviated Journal  
  Volume 5 Issue Pages 450-460  
  Keywords A3 Journal article; Condensed Matter Theory (CMT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:21182 Serial 2596  
Permanent link to this record
 

 
Author Nikolaev, A.V.; Michel, K.H. url  doi
openurl 
  Title Microscopic theory of the rhombohedral phase and transition to the monoclinic phase of solid C70 Type A1 Journal article
  Year (down) 1996 Publication Physical review : B : condensed matter and materials physics Abbreviated Journal Phys Rev B  
  Volume 54 Issue 18 Pages 12733-12743  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Starting from a model of microscopic interactions between C-70 molecules, we have developed a theory which describes the orientational dynamics and its coupling to lattice displacements in the rhombohedral phase of C-70 fullerite. The Landau free energy is calculated. We obtain a first-order phase transition to a monoclinic structure with the space group P2(1)/m. The transition is driven by the condensation of orientational quadrupoles at the F point of the Brillouin zone of the rhombohedral lattice. We find no evidence that the monoclinic structure is connected with the freezing in of orientations around the fivefold molecular axis. We calculate the lattice strains that are associated with the transition to the monoclinic structure. The theory is compared with a range of experimental data on the phase transition.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Lancaster, Pa Editor  
  Language Wos A1996VT68200028 Publication Date 2002-07-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0163-1829;1095-3795; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.736 Times cited 5 Open Access  
  Notes Approved no  
  Call Number UA @ lucian @ c:irua:16357 Serial 2034  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: