I want to evaluate the Birch-Murnaghan Equation of State (BM-EOS) for different volumes.
I tried declaring a 1D array A
in which every element would be the answer of BM-EOS for different volumes.
B0P = 4; B0 = 30
V0 = 36; E0 = -535; R4 = -535
array A[400]
do for [i=1:400] {
A[i] = E0+(9/8*B0*V0)*((V0/((((i/100)**3)/100)**3))**(2/3)-1)**2\
+ 9/16*B0*(B0P-4)*V0*((V0/((i/100)**3))**(2/3)-1)**3\
+ R4*((V0/((i/100)**3))**(2/3)-1)**4
}
I am getting error as undefined value
. Can anyone please tell what is wrong in this Gnuplot code?
Later I will use stats
command on A
to find the minimum value.
Also, is there any other better way to find out minima of a fit function in Gnuplot? This answer did not help much: Gnuplot: How can I determine the maxima of a fit function in gnuplot?