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
    Vinylidene and the Hammond postulate (1992)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 114 (1992), S. 6133-6138 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00041a034
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Reply to the Comment: On the stability of H4 in C3v symmetry (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 3929-3930 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.454873
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    On the stability of H4 in C3v symmetry (1987)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 86 (1987), S. 5882-5883 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The electronic structure of H4 in C3v symmetry has been studied by ab initio calculations. The ground state energy minimum found in these calculations is shown by vibrational analysis to be a saddle point rather than a stable bound state. The path of steepest descent from the C3v saddle point is found to lead monotonically to dissociation into two H2 molecules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.452519
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    On the structure of the ground state of H+6 (1987)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 87 (1987), S. 771-773 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The electronic structure of H+6 has been studied by ab initio calculations. It is found that there exist two stable structures, of Cs and D2d symmetries. Post-SCF calculations suggest that the ordering of these states is determined by electron correlation, with the D2d structure lying slightly lower than the Cs structure. It is suggested that the D2d structure is formed in the recent experiments of Kirchner and Bowers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.453576
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The electronic structure and stability of NF5 and PF5 (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 1805-1813 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: An ab initio study of the electronic structure of NF5 and PF5 has been carried out using Møller–Plesset perturbation theory. Optimized geometries were calculated at the SCF and MP2 levels of theory using several basis sets, ranging from 6-31G to 6-311G(2df). A vibrational analysis indicates that NF5, in D3h symmetry, has all real frequencies, even if d orbital contributions are set to zero. Dissimilar N–F bond lengths (req=1.38 A(ring), rax=1.58 A(ring)) are found, in contrast to PF5, which exhibits nearly equal equatorial and axial bond lengths. A topological analysis of the calculated charge distribution in NF5 indicates true pentavalent coordination. Spectroscopic data for NF5 have been calculated using a scaled MP2 force field based on the known NF3 molecule. A comparison of calculated thermochemistry between NF3 and NF5 yields a predicted standard state heat of formation for NF5(g) of ΔH0f (0 K)=+25.1 kJ/mol. Our results suggest that synthesis of NF5 and other hypervalent compounds of first row atoms may be possible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.459108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The electronic structure and stability of asymmetric dinitrogen dioxide (a-N2O2) (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 88 (1988), S. 7248-7249 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The electronic structure of asymmetric dinitrogen dioxide (a-N2O2) has been studied by ab initio calculations. A stable structure in Cs symmetry, of similar geometry to FN3, is predicted for the lowest 1A' state. This structure is characterized by an IR frequency of 1206 cm−1 for the N–O stretch and exhibits a significant activation barrier (65 kJ/mol) for decomposition into N2+singlet O2. This asymmetric form of N2O2 has a heat of formation of approximately +500 kJ/mol and is potentially explosive.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.454330
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    A complete basis set model chemistry. VII. Use of the minimum population localization method (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 6532-6542 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: It is shown that localization is necessary to preserve size consistency in nonlinear extrapolations of molecular energies. We demonstrate that the unphysical behavior of Mulliken populations obtained from extended basis set wave functions can lead to incomplete localization of orbitals by the Pipek–Mezey population localization method, and introduce a modification to correct this problem. The new localization procedure, called minimum population localization, is incorporated into the CBS-QB3 and the new CBS-4M model chemistries, and their performance is assessed on the G2/97 test set. The errors found for CBS-QB3 are comparable with those for the G3 and G3(MP2) (mean absolute deviation of 1.10, 0.94, and 1.21 kcal/mol, respectively, on the G2/97 test set). The CBS-4M is less accurate than the other models (mean absolute deviation of 3.26 kcal/mol on the G2/97 test set), but can be applied to much larger systems. The modified localization method resolves several problem cases found with CBS-4 and improves the reliability of CBS-QB3. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.481224
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Structure-based design of inhibitors of purine nucleoside phosphorylase (1995)
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 51 (1995), S. 529-535 
    Details
    ISSN: 1399-0047
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Inhibitors of purine nucleoside phosphorylase may have therapeutic value in the treatment of T-cell proliferative diseases such as T-cell leukemia, in the suppression of host-versus-graft response in organ transplants, and in the treatment of T-cell-mediated autoimmune diseases. Competitive inhibitors of this enzyme have been designed using the three-dimensional structure of the enzyme determined by X-ray crystallography. This approach has resulted in the synthesis of the most potent and membrane-permeable inhibitors of purine nucleoside phosphorylase reported so far.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0907444994011704
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Calculation of relative binding affinities of purine nucleoside phosphorylase inhibitors (1995)
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 51 (1995), S. 536-540 
    Details
    ISSN: 1399-0047
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: The competitive binding of inhibitors to purine nucleoside phosphorylase (PNP) has been experimentally measured. Fast and reliable computational methods to estimate binding would allow assessment of any proposed inhibitor before its synthesis. Binding-energy calculations with a representative set of PNP inhibitors were compared to the empirical values. Relatively simple and fast calculations were executed with X-PLOR, DelPhi and SoftDock. The computational results are mixed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0907444995000448
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    A complete basis set model chemistry. III. The complete basis set-quadratic configuration interaction family of methods (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 6091-6101 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The major source of error in most ab initio calculations of molecular energies is the truncation of the one-electron basis set. A family of complete basis set (CBS) quadratic CI (QCI) model chemistries is defined to include corrections for basis set truncation errors. These models use basis sets ranging from the small 6-31 G°° double zeta plus polarization (DZ+P) size basis set to the very large (14s9p4d2f,6s3p1d)/[6s6p3d2f,4s2p1d] atomic pair natural orbital basis set. When the calculated energies are compared with the experimental energies of the first-row atoms and ions and the first-row diatomics and hydrides H2, LiH, Li2, CH4, NH3, H2O, HF, LiF, N2, CO, NO, O2, and F2, two very promising new model chemistries emerge. The first is of comparable accuracy, but more than ten times the speed of the G1 model of Pople and co-workers. The second is less than one-tenth the speed of the G1 model, but reduces the root-mean-square (rms) errors in ionization potentials (IPs), electron affinities (EAs), and D0's to 0.033 and 0.013 eV, and 0.53 kcal/mol per bond, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.460448
    Library Location Call Number Volume/Issue/Year 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...