ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    Core and valence band photoelectron spectroscopic studies of nickel oxidation in an anaerobic liquid cell (1993)
    s.l. : American Chemical Society
    Analytical chemistry 65 (1993), S. 2276-2281 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac00065a018
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The silyl anion (SiH−3): Cubic/quartic force field and anharmonic contributions to the fundamental vibrational frequencies (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 8112-8121 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Fundamental vibrational frequencies for the silyl anion have been determined using two distinct vibrational theoretical methods, namely, the standard second-order perturbation theory and Pulay's variational theory. Several full quartic force fields were determined and used in both vibrational methods. Ab initio quantum mechanical methods used to generate energy derivatives include self-consistent-field (SCF), configuration interaction with single and double excitations (CISD), and coupled cluster with single and double excitations (CCSD), in conjunction with basis sets including double zeta plus polarization (DZP), triple zeta plus double polarization (TZ2P), and TZ2P plus diffuse p functions on the silicon atom [TZ2P+diff(Si)]. SCF energy third derivatives were determined using analytic methods, while SCF fourth derivatives were determined from finite differences of third derivatives. CISD analytic energy gradients were used to generate second, third, and fourth derivatives by finite difference methods. Anharmonic corrections determined from both perturbation and variational theories are found to be quite insensitive to basis set size and electron correlation. The two theoretical methods for the treatment of vibrations have shown small but systematic differences in their prediction of anharmonic corrections. The fundamental vibrational frequencies obtained agree reasonably well with the limited available experimental results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.460094
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Symmetry breaking in the NO2 σ radical: Construction of the 2A1 and 2B2 states with Cs symmetry complete active space self-consistent-field wave functions (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 8105-8109 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Jackels and Davidson's interpretation of the symmetry-breaking problem in the NO2 radical is examined using complete active space self-consistent-field (CASSCF) wave functions. Jackels and Davidson provided a Lewis-structure analysis of the necessary forms of C2v -restricted wave functions for 2B2 NO2. In particular, C2v and single-configuration restrictions force the molecule to "choose'' between the beneficial effects of resonance and the adverse effects of inclusion of charged components in the wave function. This choice, according to Jackels and Davidson, results in a distortion to Cs symmetry in the region of the 2B2 minimum. The Cs symmetry complete active space treatment enables NO2 to achieve wave functions of proper symmetry (for both 2A1 and 2B2 states, when C2v nuclear symmetry is present) while simultaneously yielding significantly localized orbitals, thus offering a means to verify the earlier analysis. Although the Cs complete active space results contradict one important Jackels–Davidson result by predicting a very shallow C2v 2B2 energy minimum for NO2, the authors find the earlier molecular orbital picture of NO2 to be a useful tool for qualitatively understanding its electronic structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.459712
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The infrared spectrum of trimethylenemethane. Predictions of in-plane vibrational frequencies from correlated wave functions (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 1174-1179 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The infrared vibrational spectrum of trimethylenemethane (TMM) is predicted with self-consistent field and configuration interaction methods. The 3A'2 electronic ground state of TMM is described in terms of restricted Hartree–Fock theory and in light of experimental evidence. Analytic gradient methods are employed to optimize theoretical geometries for 3A2 TMM; vibrational frequencies are evaluated via analytic second-derivative techniques (self-consistent-field) and finite differences of analytic gradients (configuration interaction). The resulting IR-spectral predictions are modified to reflect average errors statistically associated with the two theoretical methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.458179
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Theoretical study of anharmonicity in the vibrational spectra of the cyclopropenyl cation and its deuterated analogs (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 4320-4329 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Completely theoretical calculations for the structure, anharmonic force field up to partial sixth order, and vibrational frequencies of C3H+3, C3H2D+, C3HD+2, and C3D+3 have been carried out. The procedure included ab initio calculation of the vibrational energy surface at the 6-311 G4* + local MP4(SDQ) level and anharmonic vibrational configuration-interaction (CI) calculation using a variational expansion in a large, well-selected harmonic oscillator basis. The geometric parameters of C3H+3 are optimized as 1.3632 A(ring) for the C–C bond length and 1.0795 A(ring) for the C–H bond length. The fundamental vibrational frequencies of C3H+3 are 3193.5, 1622.1, 1015.5, 3148.8, 1297.5, 916.2, 756.8, and 1002.7 cm−1; those of C3H2D+, (3190.6, 3144.8), 2405.3, 1580.3, 1274.7, 913.4, 1001.2, 3146.3, 1295.2, 995.4, 717.8, 916.7 and 663.6 cm−1; those of C3HD+2, are 3164.7, 2434.0 (1541.6, 1506.8), 1276.0, 672.1, 824.3, 2361.6, 1261.3, 966.7, 762.3, 960.3, and 603.9 cm−1; and those of C3D+3 are (2536.7, 2451.8), 1487.4, 837.5, 2358.1, 1256.9, 671.9, 562.6, and 823.5 cm−1. The frequencies enclosed in parentheses are for Fermi resonance pairs, the prediction of which is handled automatically by this procedure. The theoretical vibrational frequencies agree with the experimental data available from both Raman and infrared spectra with 0.5% relative mean deviation. This agreement is as good as the experimental data allow, since the experiments were carried out in condensed phases and in the presence of counterions. The first overtone vibrational frequencies of C3H+3 are also predicted. The general applicability and present limitations of the method are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.456643
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Hydrogen bonding between the nitrate anion (conventional and peroxy forms) and the water molecule (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 3379-3388 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Ab initio quantum mechanical methods have been applied to the complexes of the nitrate anion (conventional D3h NO−3 and Cs ONOO− forms) with the water molecule, namely, NO−3⋅H2O and ONOO−⋅H2O. Equilibrium geometries and vibrational frequencies for a number of energy minima on the ground state potential energy surface have been determined using analytic energy first and second derivative techniques. The highest level of theory employed is the self-consistent field method with a double-zeta plus polarization basis set. The minimum energy structure (lying ∼15 kcal/mol below separated NO−3 +H2O) incorporates two hydrogen bonds in C2v symmetry. This theoretical dissociation energy agrees well with experiment. A second, more conventional single-hydrogen-bond structure is predicted to lie 2.6 kcal/mol higher in energy. At the most reliable level of theory, no distinct minimum was found for the hydrogen bonded structure between HNO3 (nitric acid) and OH−. Several minima (high lying energetically) between ONOO− and H2O are characterized theoretically.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.459692
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    What is the lowest energy structure of the NS2 molecule? (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 3683-3687 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A paramagnetic (neutral) species, thought to be the NS2 molecule, has recently been detected by Amano using millimeter wave spectroscopy in a discharge of a mixture of N2 and CS2. Detailed theoretical studies on the possible structures of an NS2 molecule, however, had not previously been reported. This study aims to find the most probable structure for the NS2 molecule and to characterize other conceivable isomers. Among many possible structures for the NS2 species, SNS bent (2A1), SNS linear (2Πu), NS2 ring (2B1), NSS bent (2A'), and SNS bent (4A2) isomers have been investigated at the self-consistent-field (SCF) and single and double excitation configuration interaction (CISD) levels of theory with double zeta plus polarization (DZ+P) and triple zeta plus double polarization (TZ+2P) basis sets. The SNS bent (2A1) isomer has been found to be the lowest energy structure among the isomers studied in this research. This bent isomer has a bond angle of about 150 deg and has a shallow double-minimum potential, the classical barrier height to linearity being 2.5 (3.0) kcal/mol at the TZ+2P-CISD(Q) level of theory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.457825
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Theoretical study of anharmonicity in the vibrational spectrum of the perfluorocyclopropenyl cation (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 1066-1071 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Complete theoretical calculations for the structure, anharmonic force field up to partial sixth order, and anharmonic vibrational frequencies of C3F+3 have been carried out. The procedure included ab initio calculation of the vibrational potential-energy surface at the 6-311G plus double polarization plus local MP4(SDQ) level, followed by a complete, 12-mode variational solution of the vibrational Schrödinger equation using a configuration-interaction (CI) expansion from a large, well-selected harmonic oscillator basis. The geometric parameters of C3F+3 (D3h) were optimized as 1.3796 A(ring) for the CC bond lengths and 1.2615 A(ring) for the CF distances. Localized orbitals show strong π-bond character for the CF linkages, conjugated with the ring π orbital. The fundamental vibrational frequencies of C3F+3 are 1999.5, 742.8 (a'1); 767.3 (a2); 1596.9, 998.9, 271.3 (e'); 250.0 (a‘2); and 664.1 (e‘). These frequencies agree with condensed phase measurements of Raman and infrared spectra with a ±11.5 cm−1 average deviation, the largest difference appearing for the CF bending and wagging frequencies. The first vibrational overtone frequencies of C3F+3 are also predicted. This completely ab initio calculation of anharmonic frequencies also leads to detailed bond characterization and full information on all intermode interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.457231
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Naked organosulfur clusters: The infrared spectrum of the C2S molecule (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 3714-3717 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Energetically low-lying states of C2S molecular systems are studied by ab initio self-consistent-field (SCF) theory and configuration interaction with all single and double excitations (CISD). Standard double-ζ plus polarization (DZP), triple-ζ plus double polarization (TZ2P), and TZ2P augmented by f-type function (TZ2P+f ) basis sets have been used for full geometry optimization and harmonic vibrational frequency analysis. For the linear 3Σ− ground state, the C–C bond length is predicted to be 1.304 A(ring), the C–S bond length is 1.550 A(ring) and the harmonic vibrational frequencies are 1728, 917, and 337 cm−1 at the TZ2P+f CISD level of theory. Results for other linear and ring states are also reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.461874
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Ammonia alane (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 5310-5317 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Ab initio studies employing basis sets approaching triple-ζ plus double-polarization plus f function quality are reported for AlH3NH3, AlH3, and NH3. The self-consistent-field method was employed for all basis sets; the single and double excitation configuration interaction and the comparable coupled-cluster methods were utilized with a double-ζ plus polarization functions basis set. The dissociation energy of AlH3NH3 is predicted to be 26 kcal/mol after correcting for zero-point vibrational energy, in qualitative agreement with the rough estimate of 30 kcal/mol by Haaland for Al–N bond strengths. In keeping with the dative nature of the Al–N bond, the AlH3 and NH3 moieties do not undergo large changes upon the formation of AlH3NH3. The resemblance of AlH3NH3 to the related compound BH3NH3 is quite strong. The equilibrium geometry, harmonic vibrational frequencies, infrared intensities, atomic charges, and dipole moment of ammonia alane are reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.462716
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...