mirror of https://github.com/abinit/abinit.git
31 lines
635 B
Gnuplot
31 lines
635 B
Gnuplot
set terminal postscript eps enhanced 22
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set output 'sigma.eps'
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set xrange [-5:5]
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#set yrange [-0.012:0.01]
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set ylabel 'sigma (10^{-5} a.u.)'
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set xlabel 'Electric field (10^{-4} a.u.)'
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set size 1,1
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set ticscale 2
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set border 15 linewidth 1.5
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set xtics 2
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set mxtics 2
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Ha_eV = 27.2113834
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Bohr_Ang = 0.5291772083
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e_Cb = 1.602176462e-19
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HaBohr3_GPa=Ha_eV/Bohr_Ang**3*e_Cb*1.0e+21
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f(x) = a*x + b
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fit f(x) 'sigma.lst' u 1:2 via a,b
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plot "sigma.lst" u ($1*10000):($2*1e5) notitle w p pt 6 ps 2, \
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f(x/10000)*1e5 notitle w lines -1
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print "piezoelectric constant = ", -a*e_Cb/(Bohr_Ang*1.0e-10)**2
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set terminal x11
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set size 1,1
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replot
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