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
Filter
  • Articles  (451,886)
  • Wiley-Blackwell  (389,696)
  • American Institute of Physics (AIP)  (54,371)
  • American Geophysical Union
  • Chemistry and Pharmacology  (451,886)
Collection
Source
Keywords
Publisher
Years
Journal
Topic
  • 1
    Electronic Resource
    Electronic Resource
    Raman scattering evidence of a ferroelastic distortion at 105 K in K2ZnCl4 (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 6181-6186 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Raman scattering measurements on K2ZnCl4 have been performed from 20 up to 250 K in the lattice mode frequency range and in the Zn–Cl stretching mode region. The splitting of certain modes in the low-frequency region and a change in the slope of the frequency vs temperature plot at 105 K show the existence of a phase transition at this temperature. Characteristic phenomena are also observed for the phase transition near 150 K.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.463726
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Molecular structure of protonated cyanogen, HNCCN+, by millimeter-wave spectroscopy (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 6187-6190 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The rotational spectra of the four monosubstituted isotopomers of protonated cyanogen HN13CCN+, HNC13CN+, H15NCCN+, and HNCC15N+, in the ground vibrational state have been investigated in the spectral region from 130–270 GHz, using a negative glow discharge production method. From the moments of inertia of the five monosubstituted species, including the DNCCN+ isotopomer [G. Cazzoli et al., Chem. Phys. Lett. 194, 297 (1992)] and of the parent species HNCCN+ [T. Amano and F. Scappini, J. Chem. Phys. 95, 2280 (1991)], the complete rs structure has been obtained. The alchemy of the ion production has been further improved compared to the previous works.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.463984
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Reduction of the two-dimensional master equation to a Smoluchowsky type differential equation with application to CH4→CH3+H (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 8673-8679 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A master equation (ME) approximation describing the effect of vibrational/rotational (V/R) relaxation on unimolecular reactions in the gas phase is presented. It is demonstrated that some forms of ME can be transformed exactly to an effective two-dimensional Smoluchowsky type differential equation (SE) in the V/R energy variables, V and R. The SE allows interpretation in a unified way of both weak and strong collision limits. Analytical expressions for the unimolecular reaction rate coefficient ku(T) are derived for simple models of the energy dependence of the microscopic reaction rate k(V,R) and V/R density of states. For realistic k(V,R) (obtained from flexible transition state theory for the reaction CH4→ArCH3+H) the SE is solved numerically. Both numerical and analytical calculations show that the collisional rotational energy transfer can, in principle, affect the rate coefficient ku(T). However, for the particular reaction considered, ku is found to be less sensitive to changes in the average rotational energy transfer than to changes in the average vibrational energy transfer. Furthermore, the strong collision limit is achieved only for unrealistically large values of the average rotational energy transfer. This means that it is a good approximation in this case one can treat V/R energy transfer and dissociation by a one-dimensional master equation in total energy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.464474
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The X˜ AlOH–X˜ HAlO isomerization potential energy hypersurface (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 8704-8709 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Ab initio molecular electronic structure theory has been used to study the AlOH–HAlO unimolecular isomerization reaction on the singlet ground state potential energy surface. Electron correlation effects were included via configuration interaction and coupled-cluster methods. Basis sets as complete as triple zeta plus two sets of polarization functions and a set of higher angular momentum functions [TZ(2df,2pd)] were employed. The classical barrier for hydrogen migration from X˜ HAlO to X˜ AlOH is predicted to be 38.4 kcal mol−1 using the TZ(2df,2pd) basis set with the coupled-cluster method including all single and double excitations with the effect of connected triple excitations included perturbatively [CCSD(T)]. After correction for zero-point vibrational energies (ZPVEs), an activation energy of 36.6 kcal mol−1 is obtained. The ΔE for isomerization is −42.2 (−40.5 with ZPVE correction) kcal mol−1 at the same level of theory. The dipole moments of HAlO and AlOH in their equilibrium geometries are 4.525 and 1.040 Debye, respectively, at the same level of theory. A comparison is also made between a theoretically predicted harmonic vibrational frequency and a recently determined experimental fundamental frequency for X˜ AlOH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.464478
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Electrostatic potential, polarization, shielding, and charge transfer in endohedral complexes of the C60, C70, C76, C78, C82, and C84 clusters (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 8734-8741 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The theory of bonding in endohedral complexes is generalized to carbon clusters other than C60. Parameters that determine electronic properties of endohedral complexes, such as their complexation energies, shifts in ionization potentials, and dipole moments, are calculated for the C70, C76, C78 (2 isomers), C82 and C84 (2 isomers) host cages. In addition, conditions for the presence/absence of electron transfer in endohedral complexes of these carbon clusters are derived and orientational preferences of guests are determined. Trends in the calculated quantities associated with increasing host cage sizes are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.464481
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Use of canonical orbital energy derivatives for closed-shell self-consistent-field wave functions (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 8749-8760 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The characteristics of the first and second derivatives of the canonical orbital energies for the closed shell self-consistent-field (SCF) wave function have been studied. The first derivatives of the orbital energies were determined analytically and the second derivatives by the finite difference method. These derivatives were transformed from the Cartesian coordinate system to the normal coordinate system for a variety of stationary points. It is demonstrated that the first and second derivatives of the orbital energies in terms of the normal coordinates provide very useful chemical information concerning the molecular structures and unimolecular reactions for a range of chemical species. Similarities and differences between the present approach and Mulliken–Walsh method are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.464483
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Theoretical study of the lowest 5Π and 5Σ+ states of CO (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 8785-8789 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The lowest 5Π and 5Σ+ states of CO are characterized using very large one-particle basis sets and the internally contracted multireference configuration–interaction treatment of electron correlation. It is found that the (1)5Σ+ state is weakly bound (De=572 cm−1) with an re of 4.76 a0, in good agreement with earlier theoretical calculations by Rosenkrantz et al. [Theor. Chim. Acta 82, 153 (1992)]. The (1)5Π state (hereafter designated a‘ 5Π) has a weakly bound outer well (De=18 cm−1, re=5.80 a0) and a significantly bound inner well (De=6043 cm−1, re=2.76 a0). It is shown that the emission spectrum between about 360 and 520 nm observed by Bahrdt et al. [Chem. Phys. 144, 273 (1990)] can be assigned to the a‘ 5Π−a' 3Σ+ and a‘ 5Π−d 3Δ transitions. Franck–Condon factors are presented to aid in the experimental identification of the a‘ 5Π state by absorption from the low-lying triplet states of CO.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.464487
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Theoretical investigation of the insertion of nickel in the CH bond of CH4. Electronic structure calculations and dynamics (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 8810-8818 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The insertion of a nickel atom in the CH bond of CH4 is calculated using density functional theory by determining the transition state and the dissociated state of HNiCH3. A barrier for nickel insertion of 40.7 kJ/mol is found and its origin is discussed. The insertion is exothermic by 34.0 kJ/mol. From the potential energy surface at the transition state and the dissociated state vibrational and rotational frequencies are obtained. Unimolecular and bimolecular transition state theory is used for the calculation of rate constants, sticking coefficients, and activation energies for the nickel insertion reaction as well as the nickel elimination reaction. Activation energies for nickel insertion in both CH4 and CD4 are small compared with other theoretical work. A moderate kinetic isotope effect for the insertion reaction is found when all hydrogens are substituted by deuterium, whereas no significant kinetic isotope effect is found for nickel elimination. Hydrogen tunneling corrections on rate coefficients are also evaluated, but their effect is negligible. Sticking coefficients are small, which is consistent with experimental sticking coefficients of CH4 on nickel surfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.464490
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Linear response Fano–DeVoe polarizability theory for biopolymers composed of chiral chromophores: Infinite order dipole–dipole approximation calculations of circular dichroism and ultraviolet band shapes of α-helical and β-pleated polypeptides (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 8835-8842 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The first order dimer model made by Stiles and Buckingham for predicting optical activity has been extended up to an infinite order N-mer model within the framework of the Fano–DeVoe type dipole approximation. The present formalism involves four mechanisms (1) the Kirkwood–Moffitt coupled oscillator mechanism through the Coulombic interactions; (2) the local asymmetric mechanism due to the intrinsic monomer optical activity; (3) the indirect electric–magnetic coupling mechanism through the Coulombic interactions; (4) the Condon, Alter, Eyring (CAE) direct electric–magnetic coupling mechanism through the electrostatic interactions between the upper to upper state transition moments on a certain site and the permanent dipole moments on the other sites. However, mechanism (4) must be excluded if we follow the Fano–DeVoe approximation, whereas it is indispensable for circular dichroism (CD) calculations of polypeptides to incorporate the CAE electric–magnetic coupling mechanism. This requirement is attained by assuming the intra-amide monomer intensity borrowing of the very weak 210 nm region nπ* state from the strong 190 nm region ππ* state through the CAE electrostatic interactions on the basis of the Schellman–Oriel perturbation equation and the Bayley–Nielsen–Schellman secular matrix theory. The present theory has particularly well predicted the CD band shapes of α-polypeptides even with the dipole approximation. The contributions due to the asymmetric fields have been found to become specifically large, while the coupled oscillator mechanism has been calculated to be a leading term.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.464493
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Mobilities of positive ions in sulfur hexafluoride gas (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 8888-8891 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The mobilities of the ions SF2+, SF3+, SF4+, SF5+, and S2F7+ in SF6 gas have been measured using an electrical shutter method with an electron ionization ion source. Measurements were made at gas temperatures of 22–36 °C over a range of E/N, the ratio of electric field strength to gas number density, from 55–550 Td (1 Townsend (Td)=10−17 V cm2) and over the pressure range 0.1–0.7 Torr. The zero-field reduced mobilities of SF2+, SF3+, SF4+, SF5+, and S2F7+ were determined to be 0.64, 0.61, 0.64, 0.65,and 0.48 cm2 V−1 s−1, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.464446
    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...