BUCKINGHAM-POTENTIAL PARAMETERS AND RELATIONS BETWEEN THEM FOR SOLIDS

Parameters m and n in the Buckingham potential in the form Phi = [U(0) mn/(m - n)]{(1/m)Y--m - (1/n)exp[n(l - Y)]} have been calculated for 7 9 elements and 35 compounds, which have been compared with data on eps ilon = c(n)u/(beta U-0) and gamma = KV0 beta and gamma = KVO beta/c(n) u, in which U-0 is the cohesion energy, gamma = (V/Va(0))(1/3), V a vo lume with equilibrium value V-0, E... C(n)u the specific heat, beta th e thermal-expansion coefficient, and K is the bulk elastic modulus. It is found that m is dependent essentially on epsilon and n on gamma. T hese relationships have been approximated, and conclusions are drawn f rom them about the most reliable input data, particularly K because of the large spread in published values. A study is made on the relation of m and n to the positions of the elements in the periodic system an d the electron structures.