Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Fourier representation method for accurate evaluation of the Coulomb and exchange lattice sums in extended chains (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 101 (1994), S. 10717-10729 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: By considering chains of hydrogen and helium atoms with one Gaussian function centered on each atomic sites, i.e., the simplest possible metallic and insulating model systems retaining all the characteristics of the restricted Hartree–Fock–Roothaan method for extended chains, a scheme is proposed to carry out accurately and efficiently both Coulomb and exchange lattice sums which occur in a Gaussian basis set environment. © 1994 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.467884
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Efficient electronic structure calculations for systems of one-dimensional periodicity with the restricted Hartree–Fock–linear combination of atomic orbitals method implemented in Fourier space (2000)
    Springer
    Theoretical chemistry accounts 104 (2000), S. 350-357 
    Details
    ISSN: 1432-2234
    Keywords: Key words: Restricted Hartree ; Fock ; Fourier space ; Gaussian-type functions ; Polymers ; Band structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract.  Formulas are presented for restricted Hartree–Fock (RHF) calculations on systems with periodicity in one dimension using a basis set of contracted spherical Gaussians. Applying Fourier-space and Ewald-type methods, all lattice sums appearing in the formulation have been brought to forms exhibiting accelerated convergence. Calculations have been carried out for infinite chains of Li2 molecules and a poly(oxymethylene) chain. The methods used here yield results that are far more precise than corresponding direct-space calculations and for the first time show the vanishing of the RHF density of states at the Fermi level for situations of partial band occupancy. Our initial computational implementation was about 5 times slower than the fastest direct-space RHF code, but improvements in special-function evaluations and numerical integrations over the Brillouin zone are shown to remove this disparity in computing speed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002140000151
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    FSGO band structure calculations of polyethers in Fourier space (1998)
    Springer
    Theoretical chemistry accounts 98 (1998), S. 155-164 
    Details
    ISSN: 1432-2234
    Keywords: Key words: Restricted Hartree-Fock ; Fourier space ; Floating spherical Gaussian orbital ; Polymers ; Band structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract. The performance of floating spherical Gaussian orbital basis sets in the description of specific but subtle cooperative interactions such as those occurring between hydrogen atoms (hyperconjugation) or between lone pairs is discussed. The calculations on infinite chains are performed using a Fourier representation of the restricted Hartree-Fock equations. The principle advantage of the method is to ensure that the lattice summations appearing in the Coulomb and exchange terms are carried out accurately and efficiently.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002140050288
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Dependence of the electronic structure on the chain geometry in stereoregular polypropylene: An exploratory theoretical study (1994)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 52 (1994), S. 469-480 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio RHF/STO-3G band structure calculations are carried out on extended regular polypropylene chains (isotactic helical, syndiotactic helical, and zigzag planar) to assess qualitatively the dependence of the energy band structure and density of states on the molecular geometry. It is found that discrimination between the two syndiotactic form should be possible from spectral features in the valence region of corresponding PS spectra. © 1994 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560520843
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    RHF Ab initio electronic and molecular structures of a ((SINGLEBOND)Be2(SINGLEBOND))∞ chain (1996)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 57 (1996), S. 871-879 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ab initio RHF/STO-3G, 3-21G, and 6-31G band structure calculations were carried out on an extended regular chain of beryllium atoms ((SINGLEBOND)Be2(SINGLEBOND))∞ to study its stability in comparison with corresponding data on finite chains and previously reported results on small elemental beryllium clusters. It is found that, starting from a linear distribution of atoms along the chain, the system evolves toward a regular zigzag planar structure. The total RHF energy per constituent atom is higher for the chains than for the clusters and is thereby suggestive of that isolated chains are unlikely to exist except in constraining channels of host structures. In the limit of the infinite chain, there are signs indicating that the RHF model is no longer an adequate description. © 1996 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 6
    Electronic Resource
    Electronic Resource
    Numerical study of the exchange effects in the valence and core energy bands of the metallic lithium chain (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 63 (1997), S. 709-718 
    Details
    ISSN: 0020-7608
    Keywords: Fourier space ; band structure ; density of states ; lattice summations ; RHF metallic solution ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Minimal basis-set STO-3G calculations on the infinite metallic chain of lithium atoms, (SINGLE BOND Li SINGLE BOND)x, performed within the Fourier space-restricted Hartree-Fock approach (FS-RHF), are reported to illustrate that the Fourier representation method, in which all lattice summations are accurately carried out to infinity, is able to reproduce the genuine features of the RHF approach for the metallic cases, i.e., the vanishing of the density of states at the Fermi energy. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 709-718, 1997
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 7
    Electronic Resource
    Electronic Resource
    Fourier space for accurate ab initio RHF band structure calculations on chainlike systems (1996)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 60 (1996), S. 1487-1497 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Minimal basis-set (STO-3G) direct and Fourier space restricted Hartree-Fock (RHF) calculations on the infinite regular (metallic) and alternating chains of lithium molecules, (-Li2-)x, are reported to illustrate two advantages of the Fourier representation method: accurate calculation of all lattice summations and faithful reproduction of the genuine features of the RHF approach for metallic cases. © 1996 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 8
    Electronic Resource
    Electronic Resource
    Advantages of the Fourier space RHF band structure approach: Application to polyoxymethylene using a distributed basis set of s-type Gaussian functions (1998)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 70 (1998), S. 1045-1054 
    Details
    ISSN: 0020-7608
    Keywords: restricted Hartree-Fock ; Fourier space ; Gaussian-type functions ; polymers ; band structure ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this contribution, we outline the Fourier space-restricted Hartree-Fock (FS-RHF) approach to the calculation of the band structure of polyoxymethylene (POM) using a distributed basis set of s-type Gaussian functions (DSGF) to simulate p-type functions. The band structure results are compared to those obtained using minimal STO-3G basis sets, within the conventional RHF direct space (DS) approach, and subminimal floating spherical Gaussian orbital (FSGO) basis sets. While the FSGO basis sets are unable to describe correctly the oxygen lone pairs and their interactions, the DSGF basis set reproduces qualitatively the features of the band structure observed with the minimal basis set. We show that minor differences between the FS and DS results originate in difficulties of lattice summations within the DS approach, illustrating the advantages of the FS method compared to the conventional DS approach.   © 1998 John Wiley & Sons, Inc. Int J Quant Chem 70: 1045-1054, 1998
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...