!cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
! bands-empty-SC-lattice.f90
! calculate the first bands along the Gamma - R=(pigr/a)(111) direction
! units are \hbar^2\pigr^2 / (2ma^2)
!cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
program bands
implicit none
integer :: n1, n2, n3, i, steps=50, m=1
real :: x,e
open (unit=1, file='bands.dat')

kpoints: do i= 0,steps
x = float(i)/steps

do n3 = -m,m
do n2 = -m,m
do n1 = -m,m
e = 3*x**2 + 4*x*(n1+n2+n3) + 4*(n1**2+n2**2+n3**2)
write(1,*)i,e
end do
end do
end do

end do kpoints
close (1)

end program bands