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Volumn 108, Issue 31, 2004, Pages 11760-11773

Mixed quantum/classical molecular dynamics simulations of the hydrated dielectron: The role of exchange in condensed-phase structure, dynamics, and spectroscopy

Author keywords

[No Author keywords available]

Indexed keywords

ENERGY SURFACE; MECHANICAL EXCHANGE; POLAR SOLVENT; TRIPLET CHARGE DISTRIBUTION;

EID: 4143060146     PISSN: 15206106     EISSN: None     Source Type: Journal    
DOI: 10.1021/jp048951c     Document Type: Article
Times cited : (16)

References (67)
  • 9
    • 17444387784 scopus 로고
    • The path-integral method for solvated electrons is reviewed by Chandler and Leung (ref 2). Explicit path-integral calculations for the hydrated electron may be found in Wallqavist, A.; Thirumalai, D.; Berne, B. J. J. Chem. Phys. 1987, 86, 6404 and Laria, D.; Wu. D.; Chandler, D. J. Chem. Phys. 1991, 95, 4444 and references contained therein.
    • (1987) J. Chem. Phys. , vol.86 , pp. 6404
    • Wallqavist, A.1    Thirumalai, D.2    Berne, B.J.3
  • 10
    • 0001318707 scopus 로고
    • and references contained therein
    • The path-integral method for solvated electrons is reviewed by Chandler and Leung (ref 2). Explicit path-integral calculations for the hydrated electron may be found in Wallqavist, A.; Thirumalai, D.; Berne, B. J. J. Chem. Phys. 1987, 86, 6404 and Laria, D.; Wu. D.; Chandler, D. J. Chem. Phys. 1991, 95, 4444 and references contained therein.
    • (1991) J. Chem. Phys. , vol.95 , pp. 4444
    • Laria, D.1    Wu, D.2    Chandler, D.3
  • 22
    • 0004279312 scopus 로고
    • Wiley: New York or Bladamer et al. in ref 3
    • See, e.g., Hart, E. J.; Anbar, M. The Hydrated Electron; Wiley: New York, 1970 or Bladamer et al. in ref 3.
    • (1970) The Hydrated Electron
    • Hart, E.J.1    Anbar, M.2
  • 29
    • 4143135204 scopus 로고
    • A notable exception is the study of the band structure of electrons in a liquid which treated electron-electron interactions at the level of Hartree-Fock theory: Kavanaugh, T.; Stratt, R. M. J. Chem. Phys. 1994, 700, 3028.
    • (1994) J. Chem. Phys. , vol.700 , pp. 3028
    • Kavanaugh, T.1    Stratt, R.M.2
  • 40
    • 4143072375 scopus 로고    scopus 로고
    • note
    • Our dielectron trajectories were assembled by concatenating several shorter runs, and at the beginning of each of these runs, the coordinates were shifted so as to place the dielectron at the center of the simulation box. By keeping track of these shifts, we can convert our simulated positions (all of which are inside the box) into global coordinates and thus calculate the diffusion constant, D.
  • 42
    • 4143061249 scopus 로고    scopus 로고
    • note
    • As was discussed in detail in ref 16, the approximations made in the CI-with-important-states algorithm lead to a small drift in the total energy of ∼0.1 eV/ps. Although temperature is relatively constant despite this drift, to reduce fluctuations of temperature, we have rescaled the magnitudes (but not the directions) of the classical velocities every 2 ps, so as to maintain a constant average temperature.
  • 49
    • 4143108913 scopus 로고    scopus 로고
    • note
    • We have defined the Coulomb and exchange energies (ref 16) such that if the two-electron state consists of a single product basis state with both electrons in the same single-electron state, a will be one.
  • 50
    • 4143127602 scopus 로고    scopus 로고
    • note
    • The sphericity order parameters, n reported in ref 24 are ∼0.1 and ∼0.2 for the "compact" and "dumbbell" dielectrons, respectively. These values compare favorably to the values of our singlet and triplet dielectrons, as reported in Table 1.
  • 51
    • 4143116586 scopus 로고    scopus 로고
    • note
    • The standard deviations in Table 1 were calculated by computing the root-mean-square deviation and dividing by the square root of the number of independent samples, which was taken to be the length of the run divided by the decorrelation time of the listed property (typical decorrelation times were ∼0.2-1 ps for dielectrons and ∼2 ps for the single electron).
  • 52
    • 0038115241 scopus 로고    scopus 로고
    • The pseudopotential we use produces a much more spherically symmetric single-electron charge density than has been reported in the recent ab initio density-functional calculations of Parinello et al., Phys. Rev. Lett. 2003, 90, 226403-1. The moments of inertia that they report for their (single) electron correspond to n = 0.27, which is much larger than we find (Table 1). We do note, however, that the density-functional calculations of Kaukonen et al., ref 24, used a different electron-water pseudopotential than the one we use, and they report values of n for the "compact" dielectron very similar to those reported here for the singlet dielectron.
    • (2003) Phys. Rev. Lett. , vol.90 , pp. 226403-226411
    • Parinello1
  • 53
    • 4143114429 scopus 로고    scopus 로고
    • note
    • 3, after forcing the vector at each time to have the maximum overlap with the vector at the previous time.
  • 54
    • 4143106701 scopus 로고    scopus 로고
    • note
    • The average root-mean-squared fluctuation for the two angles that describe the orientation in spherical coordinates is less than 30°.
  • 56
    • 4143086929 scopus 로고    scopus 로고
    • note
    • 2/5, and the results in Table 1 imply that a = 2.5 Å and c = 5.8 Å for this model of the triplet dielectron.
  • 58
    • 4143057949 scopus 로고    scopus 로고
    • note
    • n are the single-electron eigenenergies involved in the transition.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.