// Scilab Code Ex 1.26 Page-36 (2006) clc; clear; a_Rh = 3.80; // Lattice constant of Rh, angstrom a_Pt = 3.92; // Lattice constant of Pt, angstrom a_Pt_Rh = 3.78; // Lattice constant of unit cell of Pt-Rh alloy, angstrom V = (a_Pt*1e-08)^3; // Volume of unit cell of Pt, metre cube V_90 = 0.9*V; // 90 percent of the cell volume of Pt, metre cube // For x = 20% of Rh in Pt-Rh alloy, we have // a_Pt_Rh = ((1-x)*a_Pt + x*a_Rh), solving for x x = poly(0, 'x'); x = roots (a_Pt_Rh - a_Pt + x*a_Pt - x*a_Rh); // Amount of required Rh in Pt to change the unit cell volume printf("\nThe amount of Rh required in Pt to change the unit cell volume = %4.2f percent", x); // Result // The amount of Rh required in Pt to change the unit cell volume = 1.17 percent