Radial distribution function argon atom

The average local electrostatic potential V(r)/p(r), introduced by Pohtzer [57], led Sen and coworkers [58] to conjecture that the global maximum in V(r)/p(r) defines the location of the core-valence separation in ground-state atoms. Using this criterion, one finds N values [Eq. (3.1)] of 2.065 and 2.112 e for carbon and neon, respectively, and 10.073 e for argon, which are reasonable estimates in light of what we know about the electronic shell structure. Politzer [57] also made the significant observation that V(r)/p(r) has a maximum any time the radial distribution function D(r) = Avr pir) is found to have a minimum. 

Figure 9.2 Radial distribution function for the argon atom.

The Hartree-Fock or self-consistent field (SCF) method is a procedure for optimizing the orbital functions in the Slater determinant (9.1), so as to minimize the energy (9.4). SCF computations have been carried out for all the atoms of the periodic table, with predictions of total energies and ionization energies generally accurate in the 1-2% range. Fig. 9.2 shows the electronic radial distribution function in the argon atom, obtained from a Hartree-Fock computation. The shell structure of the electron cloud is readily apparent. 

Figure 6 The radial distribution function for a Lennard-Jones model of liquid argon at a temperature T = 300 K. A simulation cell of 35 A containing 864 atoms with periodic boundary conditions was used. The simulation was carried out by coupling each degree of freedom to an MTK thermostat, and the equation of motion was integrated using the methods discussed in Ref. 28.

Figm e 6.T shows the radial distribution function, g r), for liquid argon. To understand the details of this plot of g(r), examine the environment around a given Ar atom in the liquid, as illustrated in Figure 6.4. 

As for the one-dimensional case, the function L makes features emerge from the electron density that p itself does not clearly show. What then does the function L reveal for the spherical electron density of a free atom Because of the spherical symmetry, it suffices to focus on the radial dimension alone. Figure 7.2a shows the relief map of p(r) in a plane through the nucleus of the argon atom. Figure 7.2b shows the relief map of L(r) for the same plane, and Figure 7.2c the corresponding contour map. Since the electron density distribution is... 

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