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1.
Summary The structure of water in water/AOT/n-heptane reverse micelles has been studied as a function of the [H2O]/[AOT] ratio (W) by using the absorption IR due to O−H stretching modes in the 3800–3000 cm−1 range. The results show that the IR spectra can be expressed as a sum of contributions from bound- and bulk-like water. The
fraction of water in the two ?regions? within the water pool was evaluated as a function ofW. The ?bound? water region seems to hold 3.5 water molecules (corresponding to 7 O−H oscillators) per AOT molecule and its
formation is nearly complete atW>6.
Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994. 相似文献
2.
Summary Valence Full Configuration Interaction (FCI) calculations are reported for the N2 molecule with a 4s3p triple-zeta basis set at different distances. The size of the FCI space is more than 225 000 000 symmetry-adapted Slater
determinants. The computation requires about 1400 s of c.p.u. time per iteration on a CRAY C90, and is one of the largest
FCI calculations ever converged. Our results, as is in general the case for FCI computations, can be used to test the performance
of approximated methods used to study electronic correlation in molecules.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
3.
S. Evangelisti 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,20(1):61-69
The expansion structure of a CI vector as combination of excitations from a model-space reference determinant is investigated.
It is shown that between the linear and the exponential expansions there is a relation which is similar to the single-reference
case, if the internal excitations are adsorbed into the reference vector. Moreover, expansions with respect to different determinants
are related by a set of linear equations. By using these two properties, a State-Specific Coupled-Cluster formalism is proposed.
Received 2 November 2000 / Received in final form 1st March 2002 Published online 28 June 2002 相似文献
4.
I. D. Petrov T. Peters T. Halfmann S. Aloïse P. O'Keeffe M. Meyer V. L. Sukhorukov H. Hotop 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(2):181-193
The even parity mp1/2
5np′ and mp1/2
5nf′ autoionizing resonances of Ar, Kr, and Xe (m=3,4,5) were investigated experimentally and theoretically by one-photon
excitation from lower-lying intermediate levels. In particular, high
resolution measurements for the Ar(nf′), Kr(12p′,8f′), and Xe(8p′)
resonances are reported; lineshape parameters for these resonances have been
derived by a Fano-type analysis, thus yielding reduced resonance widths. The
experimental spectra and the resonance parameters are compared with
theoretical calculations which are based on the configuration interaction
Pauli–Fock approach including core polarization. The measured and
calculated lineshapes are in good agreement. In addition, theoretical predictions are presented
for other resonances, which have not yet been observed experimentally, and some
systematic trends are elucidated. 相似文献
5.
É. Biémont A. Ellmann P. Lundin S. Mannervik L.-O. Norlin P. Palmeri P. Quinet D. Rostohar P. Royen P. Schef 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(2):211-219
The difficulty associated with an accurate determination of transition rates for forbidden lines in lowly ionized heavy elements
is illustrated in the case of Nd II. We have investigated the radiative decay of the low-lying metastable levels in Nd+ including the two levels
K11/2 and
I13/2. In these two particular cases, using different theoretical approaches, we find that the decay is dominated by the M1 channels
but that the E2 contributions are of the same order of magnitude. These levels have also been studied experimentally by lifetime
measurements with the heavy ion storage ring CRYRING of Stockholm University. The difficulties encountered when performing
such experiments are underlined and discussed. 相似文献
6.
H. Nieber K. Doll G. Zwicknagl 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(2):215-221
We present an ab initio study
of electronic correlation effects
in a molecular cluster derived from
the hexanuclear ferric
wheel [ LiFe6(OCH3)12-(dbm)6] PF6.
The electronic and magnetic properties of this cluster
have been studied with all-electron Hartree-Fock,
full-potential density functional calculations
and multi-reference second-order perturbation theory.
For different levels of correlation,
a detailed study of the impact of the electronic correlation on the exchange parameter
was feasible.
As the main result, we found that
the influence of the bridge oxygen atoms
on the exchange parameter is less intense
than the influence of the apical ligand groups,
which is due to the geometry of the cluster.
With respect to the cluster model approach,
the experimental value of the exchange parameter
was affirmed. 相似文献
7.
P. Indelicato J. P. Santos S. Boucard J.-P. Desclaux 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):155-170
In this paper we review the different relativistic and QED contributions to energies, ionic radii, transition probabilities
and Landé g-factors in super-heavy elements, with the help of the MultiConfiguration Dirac-Fock method (MCDF). The effects
of taking into account the Breit interaction to all orders by including it
in the self-consistent field process are demonstrated. State of the art radiative corrections are included in the calculation
and discussed. We also study the non-relativistic limit of MCDF calculation and
find that the non-relativistic offset can be unexpectedly large. 相似文献
8.
F. J. Gálvez E. Buendía A. Sarsa 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(2):161-167
Explicitly correlated wave functions including a Jastrow factor
to take into account the dynamical correlation effects, and a
multi determinant model wave function to account for the non–dynamical
correlations are used to study some metastable excited states of the
negative ions Li- and Be-.
A detailed analysis of one– and two–body properties has been carried out
for these states. In particular the single–particle density as well as both
the two–body inter electronic and center of mass densities have been obtained.
All the calculations have been performed by using the variational Monte Carlo
method. 相似文献
9.
A. A. Buchachenko G. Chałasiński M. M. Szczęśniak 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):147-153
The results of high-level ab initio calculations are reported for
the interatomic potentials describing YbHe, Yb2, TmHe and TmYb van der
Waals interactions. It is found that the interaction properties of Tm and
Yb are very similar and the interaction anisotropy in the TmHe and TmYb
complexes is very small. We analyze the long-range behavior of the isotropic
and anisotropic interaction potentials and discuss some implications for cold
and ultracold atomic collisions of the lanthanide atoms. 相似文献
10.
Rajendra R. Zope Manoj K. Harbola Rajeev K. Pathak 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,7(2):151-155
The impulse Compton Profiles (CPs) J(q) and the expectation values for some inert gas atoms (He-Kr) are computed and compared within the Harbola-Sahni (HS), Hartree-Fock
(HF) theories and a Self-Interaction-Corrected (SIC) density functional model. The Compton profiles for excited states of
helium atom are also calculated. While the calculated CPs are found to generally agree, they differ slightly from one another
for small values of the Compton parameter q and are in good agreement for large q values. The expectation values within the three theories are also found to be comparable. The HS formalism is seen to mimic HF reasonably
well in the momentum space, establishing the logical consistency of the former.
Received: 11 December 1998 / Received in final form: 20 April 1999 相似文献
11.
F. Arias de Saavedra E. Buendıa F.J. Gálvez A. Sarsa 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,13(2):201-206
A generalized Hylleraas-type basis set with three nonlinear parameters is proposed to study three-body systems interacting
via coulomb forces within the framework of non-relativistic quantum mechanics. This basis set improves the rate of convergence
with respect to previous ones, specially for non-symmetric systems and excited states of two electron atoms. Accurate binding
energies and other properties for S-states of helium-like ions, muonic molecules and the positronium negative ion are reported.
Received 21 July 2000 and Received in final form 4 October 2000 相似文献
12.
É. Biémont H.-P. Garnir P.-H. Lefèbvre P. Palmeri L. Philippart P. Quinet D. Rostohar C. J. Zeippen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(1):91-99
Oscillator strengths have been calculated for the transitions depopulating levels of the 3s23p3, 3s3p4 configurations of K V, of the 3s23p2, 3s3p3 configurations of K VI and of the 3s23p, 3s3p2, 3p3 and 3s3p3d configurations of K VII. A multiconfiguration Dirac-Fock method, incorporating the relativistic two-body Breit
interaction and quantum electrodynamics corrections due to self-energy and vacuum polarization, has been used for the calculations.
The reliability of this approach has been tested by comparison with relativistic Hartree-Fock calculations and also with some
experimental measurements performed by beam-foil spectroscopy at a beam energy of 1.7 MeV. 相似文献
13.
I. Sakho A. S. Ndao M. Biaye A. Wague 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(1):37-44
Screening Constant by Unit Nuclear Charge (SCUNC) is a new analytical method
suitable for the treatment of the properties of He-like systems. In this
paper, the possibilities of the method are demonstrated for calculating in
the framework of semi-empirical procedure, total energies, total
electron-electron interaction energies and excitation energies for
(ns2)1Se, (np2)1De and (Nsnp)1P° doubly
excited states of He-like ions. The proposed semi-empirical scheme,
leads to accurate results in good agreement as well as with available other
theoretical results than experimental data. 相似文献
14.
J.P. Santos J.P. Marques F. Parente E. Lindroth S. Boucard P. Indelicato 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,1(2):149-163
Structure and QED effects for and levels are calculated for lithiumlike U89+ trough neonlike U82+, lithiumlike Th87+ trough neonlike Th80+ and lithiumlike Bi80+ trough neonlike Bi73+. The results of the first two sets are compared with recent measurements of the transition energy in 3 to 10-electron ions. Good agreement with experiment is found for most of the observed lines. Forty-one
possible transitions are calculated for each ion in the eight ionization states, in the experimental energy range. Twenty-eight
of these transitions have not been observed, nor calculated previously. We also calculate transition rates, branching ratios,
excitation and ionization cross sections and confirm that the thirteen experimental o
bserved transitions correspond to the ones with highest relative intensities. However, we find nineteen more transitions that
could be measured in a more sensitive experiment.
Received: 5 November 1997 / Accepted: 8 December 1997 相似文献
15.
A. Surzhykov U. D. Jentschura T. Stöhlker S. Fritzsche 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(1):27-36
We apply the density matrix theory to re-investigate the radiative
electron capture into heavy ions with one valence electron. Attention
has been paid particularly to the magnetic sublevel population of the
residual ions, as described in terms of alignment parameters. Simple
method, based on an independent particle model, which takes
into account the Pauli principle, is proposed for evaluating the
alignment of the excited ionic states. By making use of this method,
detailed calculations are performed for electron capture into (initially) hydrogen-like and lithium-like europium, gold and
uranium ions, and are compared with the results of the multiconfiguration Dirac-Fock approach.As seen from the calculations
and from the comparison with available experimental results, the independent particle model provides a good estimate for the
alignment parameters of few-electron heavy ions. Therefore, our simple model may help to understand the basic properties of
the X-ray emission from heavy, few-electron ions without the need for invoking sophisticated MCDF calculations. 相似文献
16.
A simple formula for correlation energy Ec of the π electron
systems is obtained under an approximation for the electron-electron
interactions. This formula is related directly to square of the bond
order matrix and the nearest-neighbor Coulomb electron-electron
interaction. The influence of the correlation energy on the band
energy gap is discussed. The values of the correlation energy for
polyacetylene (PA) are calculated and can be compared with those for
PA obtained by other methods, including ab initio method. 相似文献
17.
A. Zaitsevskii A.P. Pychtchev 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,4(3):303-308
A simple finite-field scheme of calculations on electronic transition dipole moments in molecules by effective Hamiltonian
methods is presented and discussed. The reliability of underlying approximations is analyzed by means of the quasidegenerate
perturbation theory and corroborated by the results of pilot numerical applications.
Received: 11 May 1998 / Revised and Accepted: 20 July 1998 相似文献
18.
F. A. Gianturco T. Stoecklin 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(3):369-375
Ab initio calculations are reported for the quantum
scattering of electrons from N2O molecules in the gas phase and
for energies which range from near threshold up to about 100 eV.
Elastic integral cross-sections and angular distributions are
examined in detail and an extensive comparison is made with existing
experiments. The agreement found with the latter data is fairly good
and results are further discussed to explain the physical mechanisms
at work for this polar target. 相似文献
19.
W. Dai W. G. Sun H. Feng L. Shen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,39(3):385-389
The vibrational excitation differential cross-sections
(DCS) of low-energy electron-N2
scattering are studied using vibrational close-coupling (VCC) method and
vibrational scattering potentials which include static, exchange and
polarization contributions. By including the contributions of 18 partial
waves, 20 vibrational states, and 16 molecular symmetries (up to Λ=7), the converged vibrational excitation (0↦2, 0↦3, 0↦4)
DCS agree well with experimental results. Also obtained are converged
vibrational (1↦0, 1↦1, 1↦2, 1↦3) DCS, with the impact
energies being those of the main resonant peaks (1.92 eV, 1.90 eV, 1.62 eV,
1.63 eV). 相似文献
20.
S.I. Themelis Y. Komninos C.A. Nicolaides 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(3):277-293
This paper discusses theory and results on 1P0 doubly excited states (DES) in He and in H- of very high excitation, up to the N
= 25 manifold. Our calculations employed full configuration interaction (CI) with large hydrogenic basis sets and produced correlated
wavefunctions for the four lowest roots at each hydrogenic manifold by excluding open channels and the small contribution
of series belonging to lower thresholds. The suitability of the hydrogenic basis sets for such calculations is justified,
apart from their practicality, by the fact that, by computing from them natural orbitals, the results were shown to be the
same with those of earlier multiconfigurational Hartree-Fock (MCHF) calculations on low-lying DES. In total, 160 states were
computed, most of them for the first time. Their energy spectrum should be of use to possible future photoabsorption experiments.
For certain low-lying DES up to N
= 13, for which previous reliable results are available, comparison of the calculated energies shows good agreement. The correlated
wavefunctions contain systematically chosen single and double excitations from each hydrogenic manifold of interest. From
their analysis, we determined the “goodness" of different quantum numbers and the geometry (average angles and radii) as a
function of excitation. For the Sinano lu-Herrick (
K
,
T
) classification scheme, whose basis is a restricted CI with hydrogenic functions and which has thus far been tested only on
low-lying DES, we established that, whereas T remains a good index as energy increases, K does not. Consequently, a more flexible than K quantum number is needed in order to account for most of the additional correlation. This number, represented by F
=
N
-
K
- 1, where N and K are not good numbers anymore, produces consistently a much higher degree of purity than the (
K
,
T
) scheme does, especially as N increases and as the relative significance of various virtual excitations due to electron correlation increases. Among the
four states of each manifold, in all cases in H- and in most cases in He, the three are of the intrashell type and one is of the intershell type with (
F
,
T
) = (0, 0). The lowest intrashell states and the lowest intershell states exhibit a wide angle geometry tending to 180
°
as N
↦∞.
Received 10 September 2001 and Received in final form 12 November 2001 相似文献