On the use of symmetry in SCF calculations. The case of fullerenes and nanotubes

2012 ◽  
Author(s):  
C. M. Zicovich-Wilson ◽  
Y. Noël ◽  
A. M. Ferrari ◽  
R. Orlando ◽  
M. De La Pierre ◽  
...  
Keyword(s):  
Scf Calculations

Copolymer Micelles with Polyelectrolyte Shell in Aqueous Media. A Mean-Field Study

2006 ◽  
Vol 71 (5) ◽  
pp. 756-768 ◽  
Author(s):  
Karel Jelínek ◽  
Filip Uhlík ◽  
Zuzana Limpouchová ◽  
Pavel Matějíček ◽  
Karel Procházka
Keyword(s):  
Aqueous Media ◽  
Excitation Energy Transfer ◽  
Mean Field ◽  
Hydrophobically Modified ◽  
Small Influence ◽  
Covalently Bonded ◽  
Self Consistent Field ◽  
Copolymer Micelles ◽  
And Behavior ◽  
Scf Calculations

The multimolecular micelles formed by polystyrene-block-poly(methacrylic acid) (PS-PMA) copolymer and by hydrophobically modified PS-PMA copolymer with naphthalene and anthracene (PS-N-PMA-A) were studied by self-consistent field (SCF) calculations in aqueous media. The labeling with covalently bonded naphthalene between PS and PMA blocks and with anthracene at the free end of PMA blocks, which is suitable for experimental nonradiative excitation energy transfer (NRET) studies of PS-N-PMA-A micelles, modifies the structure of micellar shell. The study was aimed at understanding structure and behavior of micelles at different pH and ionic strength. The results show that the presence of hydrophobic tags has only a small influence on the overall structure of micelles but it strongly affects the distribution of PMA free ends. The hydrophobic labels (anthracenes) try to return into the shell and their certain fraction is localized close to the core/shell interface, which causes a fairly high NRET efficiency. The calculated and experimentally measured NRET efficiency were compared; their trends are reasonable at the semiquantitative level.

OPTICAL TRANSITIONS IN A PARABOLIC GaAs/Ga1-xAlxAs SUPERLATTICES

2001 ◽  
Vol 08 (03n04) ◽  
pp. 321-325
Author(s):  
ŞAKIR ERKOÇ ◽  
HATICE KÖKTEN
Keyword(s):  
Transition Matrix ◽  
Optical Transition ◽  
Matrix Elements ◽  
Electron States ◽  
Parabolic Potential ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Transition Matrix Elements ◽  
Scf Calculations

We have performed self-consistent field (SCF) calculations of the electronic structure of GaAs/Ga 1-x Al x As superlattices with parabolic potential profile within the effective mass theory. We have calculated the optical transition matrix elements involving transitions from the hole states to the electron states, and we have also computed the oscillator strength matrix elements for the transitions among the electron states.

Proper correction for the basis set superposition error in SCF calculations of intermolecular interactions

1987 ◽  
Vol 61 (1) ◽  
pp. 233-247 ◽  
Author(s):  
Maciej Gutowski ◽  
Frans B. Van Duijneveldt ◽  
Grzegorz Chałasiński ◽  
Lucjan Piela
Keyword(s):  
Intermolecular Interactions ◽  
Basis Set ◽  
Basis Set Superposition Error ◽  
Scf Calculations

Conformational preferences in 2-nitrophenylthiolates: interplay between intra- and intermolecular forces; structures of (E)-1-(4-methyl-2-nitrobenzenethiolato)-2-phenylethene, S-(2-nitrophenyl)benzenecarbothiolate and 1-(2-nitrophenylthio)-2,5-pyrrolidinedione

2000 ◽  
Vol 56 (1) ◽  
pp. 58-67 ◽  
Author(s):  
John N. Low ◽  
Emily J. Storey ◽  
Mary McCarron ◽  
James L. Wardell ◽  
George Ferguson ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Nitro Group ◽  
Intermolecular Forces ◽  
Aryl Ring ◽  
Local Energy Minimum ◽  
Conformational Preferences ◽  
A Chain ◽  
Related Compounds ◽  
Scf Calculations ◽  
Intramolecular Forces

In (E)-1-(4-methyl-2-nitrobenzenethiolato)-2-phenylethene, C15H13NO2S (1) (orthorhombic Pbca), the nitro group is almost coplanar with the adjacent aryl ring, but the dihedral angles between the nitro-aryl and styryl fragments is ∼121°. The molecules are linked by paired C—H...O hydrogen bonds in a chain of rings. In S-(2-nitrophenyl)benzenecarbothiolate, C13H9NO3S (2) (monoclinic P21/a), the nitro group is rotated by 33.0 (2)° out of the plane of the adjacent aryl ring and the thiobenzoate group is strongly twisted away from the plane of the disubstituted aryl ring. The molecules of (2) are linked into chains by C—H...O hydrogen bonds, and each chain is linked to two neighbouring chains by means of aromatic π...π stacking interactions. In 1-(2-nitrophenylthio)-2,5-pyrrolidinedione, C10H8N2O4S (3) (monoclinic P21/a), the nitro group is again almost coplanar with the adjacent aryl ring, but the pyrrolidinedione unit is almost orthogonal to the O2NC6H4SN plane. There are three types of C—H...O hydrogen bond in the structure, and these link the molecules into a two-dimensional net. The conformations of these molecules have been investigated by SCF calculations and two energy minima have been identified for each: the molecules of (1) and (3) adopt conformations in their crystals which are close to those at the overall energy minima calculated for isolated molecules, while molecules of (2) adopt a conformation in the crystal close to that calculated for the local energy minimum. Comparisons are made with the structures of some related compounds and it is concluded that, while the nature of the two conformational minima is determined by intramolecular forces, the choice between them is determined primarily by intermolecular forces.

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