Showing papers on "Interatomic potential published in 1975"
TL;DR: In this article, a dense random packing of 888 hard spheres has been relaxed with respect to a realistic interatomic potential, and the result is compared to the experimental pair distribution function of amorphous Co and an Amorphous Ni76P24 alloy.
Abstract: A dense random packing of 888 hard spheres has been relaxed with respect to a realistic interatomic potential. The result is compared to the experimental pair distribution function of amorphous Co and an amorphous Ni76P24 alloy. The positions of the maxima of the pair distribution function of Co are accurately reproduced. The differences between Co and Ni76P24 are discussed.
101 citations
TL;DR: In this article, the repulsive part of the pair potential between the ions in liquid metals can be obtained from the structure factor curve lying beyond the first diffraction maximum, and a general form for a repulsive potential is presented.
74 citations
TL;DR: In this article, a geometrical model for the threshold cnergy surface of a b.c. lattice is applied to analyse recent measurements of the resistivity change rates in electron-irradiated monocrystalline molybdenum specimens with the orientations [100, [11O], [111] and [112] and cross sections computed with this surface were matched to the experimental data using various sets of threshold energies as parameters.
Abstract: A “geometrical” model for the threshold cnergy surfaceof a b.c.c. lattice is applied to analyse recent measurements of the resistivity change rates in electron-irradiated monocrystalline molybdenum specimens with the orientations [100], [11O], [111] and [112]. Cross sections computed with this surface were matched to the experimental data using various sets of threshold energies as parameters. The best fit was obtained with Td [100] = (35+2 −2) eV, Td [1101 > 2Td [100], Td [111] = (45 f 3) eV. When corn ared to the experimental damage rates the absolute values for the cross sections yield a Frenkel pair resistivity pio = (13 f 2) pfl cm/at.% F.P. Expressions for the energy necessary to penetrate the potential barriers in the principal crystallographic directions are derived and compared to the id[iik] obtained before, with the interatomic potential as parameter. Taking into account the length of the [111] collision chains and the size of the spontaneous recombination volume, the appropriate poten...
44 citations
TL;DR: In this paper, the diffuse X-ray scattering has been measured from a CuAu single crystal held at 700 and 800 K and from a crystal quenched from 1070 K and held at room temperature and 126 K.
31 citations
TL;DR: In this article, a neutralization model for an energetic ion at an atomic surface is given and the reliability of this model is tested by comparison of the results of computer calculations and the measured peak intensity distributions as a function of the scattering angle.
19 citations
TL;DR: In this article, the authors calculated the fractional increase in the Clausius-Mossotti expression for the dielectric constant of a non-polar fluid on the basis of the Kirkwood-Yvon theory, assuming that the structure of the fluid is that appropriate to a Lennard-Jones interatomic potential.
Abstract: We have calculated the fractional increase in the Clausius-Mossotti expression for the dielectric constant of a non-polar fluid on the basis of the Kirkwood-Yvon theory, assuming that the structure of the fluid is that appropriate to a Lennard-Jones interatomic potential. The triplet distribution function which occurs in the Kirkwood-Yvon theory was replaced by the superposition approximation. Pair distribution functions, and relevant thermodynamic properties, for a Lennard-Jones fluid were taken from the machine simulation studies of Verlet and co-workers. We present the results at the two reduced temperatures T* = 1·5 and T* = 2·5, and compare them with (i) predictions based on the dielectric virial expansion (curtailed at the three-particle term), and (ii) some estimates by Alder, Strauss and Weis, obtained by the method of molecular dynamics. We conclude that, subject to the assumptions of the Kirkwood-Yvon theory, the dielectric virial expansion approach is adequate when the reduced density, ρ*, is l...
18 citations
18 citations
TL;DR: In this paper, an interatomic potential, essentially a mathematical approximation to Lindhard's standard potential but simpler to use, has been examined with regard to its predictions for the variation of the stopping function with the position of the ion in the channel.
Abstract: An interatomic potential essentially a mathematical approximation to Lindhard's standard interatomic potential but simpler to use, has been examined with regard to its predictions for the variation of the stopping function with the position of the ion in the channel. The variation of the interatomic potential itself with interatomic distance is found to be close to that of Lindhard's potential as well as the Moliere potential, for all values of r greater than a, the Thomas-Fermi distance. The variation of stopping function for heavy-ion (53127I) and alpha -particle channelling in the (100) and (111) planes of gold single crystals for the new (and simpler) potential is found to be reasonably close to the predictions of the Lindhard and Moliere potentials.
16 citations
TL;DR: In this article, the normal coordinate treatment of poly-1,3-dioxolane crystal form II was made using a modified Urey-Bradley force field for the normal mode calculations of the three-dimensional crystal lattice, the van der Waals intermolecular interactions for the atomic pairs of H, O ⋯ H, and C ⋾ H were taken into account along with the intramolecular force constants determined by the least-squares method.
11 citations
TL;DR: In this paper, the second layer of a monolayer plus helium film is assumed to form a quasi-two-dimensional gas and the binding energy of the second-layer atoms to the first layer is analyzed.
Abstract: A model in which the atoms in the second layer of a monolayer-plus helium film are assumed to form a quasi-two-dimensional gas is used to analyze the isotherm data of Goellner, Daunt, and Lerner for helium on Grafoil. The parameters in the model are determined by a least-squares fit of the model isotherm to the data. These parameters include the second and third virial coefficients of the quasi-two-dimensional gas and the binding energy of the second-layer atoms to the first layer. The empirical values are compared to recent theoretical predictions for the two-dimensional helium gas. The agreement and discrepancies between theoretical and empirical values are discussed. The conclusion is that the second layer (at low densities) can be described as an imperfect two-dimensional gas with perhaps some modification of the interatomic potential due to substrate effects.
5 citations
TL;DR: In this article, the most accurate neutron scattering data now available for argon have been used to calculate the interatomic potential, and comparison of results is made for two different procedures, and using several approximations for each procedure.
TL;DR: In this paper, the interatomic potential of the ground 1Σg+ state of 24Mg2 is approximated by a variety of Morse hybrid potential functions. But the need for uncoupling the two forms to produce realistic potentials is emphasized.
TL;DR: In this paper, the atomic arrangement of an α-Fe crystallite embedded in an elastic continuum is calculated using the Johnson-I interatomic potential, and a narrow dislocation without any stacking fault results, although there is some displacement in the core parallel to the dislocation line.
01 Jan 1975
TL;DR: In this paper, the authors reviewed recent computer simulation of dislocation models in α-Fe and KC1 and discussed the implications of these effects in terms of interactions of point defects with the core field.
Abstract: The highly nonlinear elastic state in the vicinity of a dislocation core is the source of a linear elastic displacement field (core field) outside the core. Recent computer simulation of dislocation models in α-Fe and KC1 have shed considerable light on the nature of the core field and these results are reviewed. An important feature of the core field is a net dilatation. A decrease in the elastic constants near the dislocation is also noted and results from the lattice expansion. The implications of these effects in terms of interactions of point defects with the core field is discussed.
01 Jan 1975
TL;DR: In this paper, the binary elastic interaction between a single Ar atom and an Au atom and the multiple collision between an Ar and two neighbouring Au atoms were investigated and the relationships between energy retained by the scattered atom and scattering angle were deduced for various incidence conditions of initial energy, impact parameter and Born-Mayer constants.
Abstract: Initially an analogue computer and subsequently a hybrid computer were used to simulate the trajectories of colliding atoms acting under a central Born-Mayer interatomic potential. Studies of the binary elastic interaction between a single Ar atom and an Au atom and the multiple collision between an Ar atom and two neighbouring Au atoms were undertaken and the relationships between energy retained by the scattered atom and scattering angle were deduced for various incidence conditions of initial energy, impact parameter and Born-Mayer constants. The results are shown to agree well with digital simulation studies and several new features of the interaction process are explored.