Browsing DFA  Artículos by Issue Date
Now showing items 120 of 204

Scattering of lowenergy electrons by polar molecules : an analytic approach
(American Physical Society, 1998)The scattering of lowenergy electrons by polar molecules is considered. The excitation to the rotational states in the sudden approximation and the effect of the Coulomb dipole force to all orders are taken into account. ... 
The vibronicallyresolved emission spectrum of disulfur monoxide S2O : an algebraic calculation and quantitative interpretation of Franck–Condon transition intensities
(American Institute of Physics, 1999)Emission spectra obtained from jetcooled disulfur monoxide (S2O) molecules have been interpreted by means of a novel Lie algebraic formalism that makes possible the facile evaluation of multidimensional Franck–Condon ... 
The interacting boson model with SU(3) charge symmetry and its application to even–even N≈Z nuclei
(Elsevier, 1999)The isospininvariant interacting boson model IBM3 is analyzed in situations where SUT (3) charge symmetry [or, equivalently, UL(6) sd symmetry] is conserved. Analytic expressions for energies, electromagnetic ... 
A quantitative study of nonCondon effects in the S2O C̃→X̃ emission spectrum
(American Institute of Physics, 2000)A novel technique has been developed for the quantitative study of vibronicallyresolved transition intensities in polyatomic molecules beyond the Condon approximation. Matrix elements of coordinatedependent transition ... 
Configuration localized wave functions : general formalism and applications to vibrational spectroscopy of diatomic molecules
(American Physical Society, 2000)A general formalism for constructing configuration localized states for onedimensional potentials is presented. It allows the evaluation of accurate approximations to the vibrational matrix elements of the momentum operator ... 
Excess Thermodynamic Properties of Chainlike Mixtures. 1. Predictions from the Soft−SAFT Equation of State and Molecular Simulation
(American Institute of Physics, 2000)Monte Carlo simulation and theory are used to calculate excess thermodynamic properties of binary mixtures of LennardJones chains. Chainlike molecules are formed by LennardJones spherical sites that are tangentially bonded. ... 
Coupling to breakup channels using a transformed harmonic oscillator basis
(American Physical Society, 2001)The application of a recently proposed procedure for discretizing the continuum to collision processes involving weakly bound nuclei is studied. In particular, the coupling to breakup states in the collision of d 1208 ... 
Instantons and the A (2) condensate
(American Physical Society, 2002)We argue that the ⟨A2OPE⟩ condensate found in the Landau gauge on lattices, when an operator product expansion of Green’s functions is performed, might be explained by instantons. We use cooling to estimate the instanton ... 
Continuum coupling in onedimensional scattering using a transformed harmonic oscillator basis
(American Physical Society, 2002)The coupling to the continuum is studied in a onedimensional problem that describes the interaction of a weakly bound composite object with a wall in a semiclassical approach. A transformed harmonic oscillator basis is ... 
The global phase diagram of the Gay–Berne model
(American Institute of Physics, 2002)The phase diagram of the Gay–Berne model with anisotropy parameters k53, k 855 has been evaluated by means of computer simulations. For a number of temperatures, NPT simulations were performed for the solid phase leading ... 
The strong coupling constant at small momentum as an instanton detector
(Springer Verlag, 2003)We present a study of αMOM(p) at small p computed from the lattice in the quenched approximation (nf = 0). It shows a dramatic proptop4 law which can be understood within an instanton liquid model. In this framework the ... 
Transparent expression of the A2 condensate’s renormalization
(American Physical Society, 2003)We give a more transparent understanding of the vacuum expectation value of the renormalized local operator A2 by relating it to the gluon propagator integrated over the momentum. The quadratically divergent perturbative ... 
Continuum discretization using orthogonal polynomials
(American Physical Society, 2003)A method for discretizing the continuum by using a transformed harmonic oscillator basis has recently been presented @Phys. Rev. A 63, 052111 ~2001!#. In the present paper, we propose a generalization of that formalism which ... 
Critical properties of molecular fluids from the virial series
(American Institute of Physics, 2003)We present results for the fourth virial coefficient of quadrupolar LennardJones diatomics for several quadrupole moments and elongations. The coefficients are employed to predict the critical properties from two different ... 
The phase diagram of the two center LennardJones model as obtained from computer simulation and Wertheim’s thermodynamic perturbation theory
(American Institute of Physics, 2003)The global phase diagram (i.e., vapor–liquid and fluid–solid equilibrium) of twocenter LennardJones (2CLJ) model molecules of bond length L=σ has been determined by computer simulation. The vapor–liquid equilibrium ... 
Third virial coefficients and critical properties of quadrupolar two center LennardJones models
(Royal Society of Chemistry, 2003)We report numerical results for the third virial coefficient of two center LennardJones quadrupolar molecules. Calculations are performed for 35 models with different elongations and quadrupoles over a temperature range ... 
Phase transitions and critical points in the rareearth region
(American Physical Society, 20030815)A systematic study of isotope chains in the rare–earth region is presented. For the chains 144−154 60Nd, 146−160 62Sm, 148−162 64Gd, and 150−166 66Dy, energy levels, E2 transition rates, and two– neutron separation ... 
Quantum Phase Transitions in the Interacting Boson Model : Integrability, level repulsion and level crossing
(American Physical Society, 20031014)We study the quantum phase transition mechanisms that arise in the Interacting Boson Model. We show that the secondorder nature of the phase transition from U(5) to O(6) may be attributed to quantum integrability, whereas ... 
The U(5)–O(6) transition in the Interacting Boson Model and the E(5) critical point symmetry
(American Physical Society, 20031024)The relation of the recently proposed E(5) critical point symmetry with the interacting boson model is investigated. The largeN limit of the interacting boson model at the critical point in the transition from U(5) to ... 
An accurate density functional theory for the vaporliquid interface of associating chain molecules based on the statistical associating fluid theory for potentials of variable range
(American Institute of Physics, 2004)A Helmholtz free energydensity functional is developed to describe the vaporliquid interface of associating chain molecules. The functional is based on the statistical associating fluid theory with attractive potentials ...