Hydrogen interatomic potential

In view of the complications of the intermolecular potential (as compared to the interatomic potential of the rare gas atoms) the comparisons for molecules in Tables II, III, and IV should be judged with caution. The apparent discrepancies from the theories for single atoms can be misleading. An example is the calculation for CH4 on the Slater-Kirkwood theory where Table IV shows the absurd value of 24 for the effective number of electrons. Pitzer and Catalano32 have applied the Slater-Kirkwood equation to the intermolecular potential of CH4 by addition of all the individual atom interactions and, with N = 4 for carbon and 1 for hydrogen, obtained agreement within 5 per cent for the London energy at the potential minimum. 

The form of the potential for the system under study was discussed in many publications [28,202,207,208]. Effective pair potentials are widely used in theoretical estimates and numerical calculations. When a many-particle interatomic potential is taken into account, the quantitative description of experimental data improves. For example, the consideration of three-body interactions along with two-particle interactions made it possible to quantitatively describe the stratification curve for interstitial hydrogen in palladium [209]. Let us describe the pair interaction of all the components (hydrogen and metal atoms in the a. and (j phases) by the Lennard Jones potential cpy(ry) = 4 zi [(ff )12- / )6], where Sy and ai are the parameters of the corresponding potentials. All the distances ry, are considered within c.s. of radius r (1 < r < R), where R is the largest radius of the radii of interaction Ry between atoms / and /). 

Nemethy C, Scheraga HA (1977) Interatomic potentials from crystal data. V. Determination of empirical parameters of OH—O hydrogen bonds from packing considerations and lattice energies of polyhydric alcohols. J Phys Chem 81 928-931... 

Several empirical and semiempirical interatomic potentials have been developed for the Si H systembased on extensions and modifications of well-known potentials for Si including up to three-body interactions (StilUnger and Weber, 1985 Biswas and Hamann, 1985 Biswas et al., 1987 Mousseau and Lewis, 1991 Baskes, 1992). Recent atomic-scale simulation work of plasma-surface interactions in the PECVD of Si thin films has been based on an empirical description of interatomic interactions in the Si H system according to Tersoff s (1986, 1988, 1989) potential for Si, as extended by Ohira and co-workers (1994, 1995, 1996) to incorporate Si-H, H-H, and the corresponding three-body interactions. The extension of the potential to include the presence of hydrogen adopted the Tersoff parametrization to fit results of ab initio calculations for the structure and energetics of Sil 1., x <4, species in the gas phase (Ohira et al., 1994,1995,1996). A similar form of... 

---