#!/usr/bin/gnuplot

f(x) = b *(x-a)**2 + f * (x-a)**3 + e

a = 4.600
b = 1
e = -22.8
f = 0.01
fit f(x) "etot.dat" via a,b,e,f

set term postscript eps enhanced color solid 28
set output "etot.eps"
#set term png enhanced lw 2 font ",20"
#set output "etot.png"
set nokey
set xlabel 'a (a_B)'
set ylabel 'Energy (Ry)'
plot f(x), "etot.dat" ps 2