#!/usr/bin/env gnuplot ## HARTREE_IN_EV = 27.21138386 set encoding iso_8859_1 set terminal postscript portrait enhanced "Times-Roman" color 24 set output "perovskite-B11-12.eps" Etot(x) = 3.0/4*B11_12 * x**2 + Emin # initial values B11_12 = 30.0 # [eV] Emin = -3587.0 # [eV] fit Etot(x) 'perovskite-B11-12.dat' using ($1):($3*HARTREE_IN_EV) via B11_12, Emin set format y "%.3f" set ylabel "{/Times-Italic E}_{tot}-{/Times-Italic E}_0 [eV]" #set origin 0.0,0.0 #set yrange [-0.005:0.020] set xlabel "{/Symbol d}" set xtics 0.01 set ytics 0.005 plot 'perovskite-B11-12.dat' using ($1):($3*HARTREE_IN_EV-Emin) t 'calculated data' w p lt 2 pt 2 ps 2 lw 3,\ 3.0/4*B11_12 * x**2 t 'quadratic fitting' w l lt 2 lw 3 print 'B11-B12 = ', B11_12, ' [eV]' #C11_12 = B11_12 / a0_Angstrom**3 * 160.22 #print 'C_11-C_12 = ', C11_12, ' [GPa]' #Local variables: # compile-command: "gnuplot perovskite-B11-12.gp" #End: