Library

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
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 2426-2427 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 6842-6849 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The semiclassical determination of N(E;J) and ρ(E;J), the specific number and density of quantum states at energy E, and fixed total angular momentum J, by Monte Carlo integration of phase space is compared to recent exact quantum calculations on H+3 and HD+2, which yielded lists of up to 900 quantum states for single values of J. This allows for the first time tests of such a procedure to be made without assuming anything about separability or harmonicity of the potentials. The excellent agreement between semiclassical and quantum state counts shows that the semiclassical numerical computation is a viable and simple method for the determination of state numbers and densities in small molecules with a precision of the order of 1%. For J=0, the procedure has been extended to state numbers for the different symmetry species occuring in H+3 and HD+2.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 3377-3386 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A study of the bound states of the H+3 molecular ion at zero total angular momentum is presented. Wave functions are shown for the accurate ab initio Meyer–Botschwina–Burton potential energy surface and the more approximate diatomics in molecules (DIM) surface. The qualitative behavior is similar for the two potentials. The analytic form of the DIM surface enables a study that reaches energies as high as the dissociation threshold. Quantum states are found to localize regularly around the horseshoe periodic orbits found in previous classical studies. There is good agreement between a semiclassical periodic orbit quantization formula and the exact quantum energies. The antisymmetric stretch frequency with respect to the orbit is estimated classically and quantum mechanically and found to be in agreement with a previous estimate. A three-dimensional stability analysis of the horseshoe orbit is presented and used as a basis for the semiclassical theory. The implications on the assignment of the coarse grained photodissociation spectrum measured by Carrington and Kennedy are discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 3005-3017 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Two degrees of freedom quantum mechanical calculations on the bound states of H+3 are presented. Two different potential energy surfaces are employed. The effect of rotational excitation is analyzed. For J=0, the high energy region is composed largely of states that cannot be assigned. However, two regularly spaced series are observed, corresponding to "horseshoe'' states predicted previously by classical calculations. In addition we find a new assignable series of inverted hyperspherical states. Conversely, for high orbiting angular momentum (l=20) in which the proton rotates about the diatom, assignable normal mode states persist up to dissociation. Semiclassical periodic orbit quantization is found to give excellent agreement for the regular quantum states. The significance of these results for the interpretation of the H+3 photodissociation spectrum is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 3815-3825 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A formulation of the rovibrational problem in Jacobi coordinates is presented which employs a discrete variable representation for the angular internal coordinate. Rotational excitation is implemented via a two-step procedure and symmetry (for AB2 systems) included using a computationally efficient method. Energies for the lowest 180 vibrational states of H+3 are presented and their wavefunctions analyzed graphically. J=1←0 excitation energies are presented for the lowest 41 vibrational states. The significance of the regular states in the high-energy regime of H+3 is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 2178-2184 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The two-dimensional interaction potential of the N+2(X 2Σ+g) –He(X 1S) system has been calculated using highly correlated ab initio MCSCF-CI wave functions for a fixed value of the N+2 bond length (2.110 a0). It is found to have a minimum about 140 cm−1 below the N+2 +He dissociation limit, significantly deeper than the minimum in the neutral system N2–He. This well depth is enough to give rise to a cluster-like, bound structure with a considerable number of vibration–rotation levels in the electronic ground state. The well depth is almost independent of the N2–He angle, which leads to large amplitude bending motions. Rovibrational calculations have been performed on the surface for J=0, 1, and 2. Values for the rotational constant B, the fundamental stretching frequency νs, and its first and second overtones, and the rotational constant Cn in each nνs manifold, have been obtained from the energy levels computed. It is found that B=1.879 cm−1, 1νs =55.231 cm−1, 2νs =83.404 cm−1, 3νs =92.491 cm−1, C0=0.477 cm−1, C1=0.370 cm−1, and C2=0.254 cm−1. Estimates of the accuracy of these parameters are made.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 2524-2524 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The neutral–neutral and ion–neutral reactions of Mu, Mu+, HMu, and HMu+ with H, H2, H+2, and H+3 are considered. Vibrational zero-point energy effects make the Mu–H exchange reactions endothermic and suggest that little molecule formation occurs in room temperature Mu–H2 mixtures.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 906-918 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The structure of bending overtones of the H3+ and D3+ molecular ions at the energies below the barrier to linearity is analyzed using energies and wave functions from full three-dimensional discrete variable representation calculations. The lowest-in-energy states of the vibrational polyads ν2=4,5,6 are shown to follow the localization pattern of local bending modes, three equivalent-by-symmetry principal periodic trajectories of the corresponding classical two-mode system near the equilibrium.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 7191-7203 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The 3D discrete variable representation (DVR) calculations of Henderson and Tennyson [Chem. Phys. Lett. 173, 133 (1990)] are reanalyzed to find the source of the nonvariational behavior highlighted by Carter and Meyer [J. Chem. Phys. 96, 2424 (1992)]. The discrepancy is found to be caused not by the use of incorrect boundary conditions, but by a failure of the quadrature approximation commonly used in DVR calculations. Corrected DVR calculations show variational but slow convergence. Calculations using the same intermediate vectors as the nonvariational calculations and a corrected final Hamiltonian show greatly enhanced convergence. The vibrational band origins computed with this method are converged to within 2 cm−1 up to 35 000 cm−1. A complete list of these is presented and comparisons made with previous predictions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 10433-10438 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: High resolution spectroscopic data for H3+, H2D+, D2H+, and D3+ is used to determine effective, mass-dependent potential energy surfaces for each isotopomers. These surfaces are expressed as a sum of the mass-independent Born–Oppenheimer (BO) potential and a mass dependent adiabatic correction. For H3+ and D3+ the adiabatic correction is a single surface of the same symmetry and functional form as the BO surface. For H2D+ and D2H+ a second, lower symmetry surface is required. Fits to all three surfaces were started from recent, high quality ab initio calculations. The standard deviations for fits using all the available data with J≤9 are 0.015 cm−1 for H3+, 0.010 cm−1 for H2D+ and D2H+ combined, and 0.015 cm−1 for D3+. These values are close to the intrinsic experimental error of much of the data and improve on the corresponding ab initio surfaces by at least an order of magnitude. The fits are very compact: nearly 1600 data are fitted by adjusting 36 constants and freezing 51 at their ab initio values. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...