Update 8_many_atoms.md

src/8_many_atoms.md

@@ -100,7 +100,7 @@ pyplot.yticks([], [])
 pyplot.vlines([-pi, pi], 0, 2.2, linestyles='dashed')
 pyplot.legend()
 pyplot.xlim(-1.75*pi, 3.5*pi)
-pyplot.ylim(bottom=-0.6)
+pyplot.ylim(bottom=0)
 ax.annotate(s='', xy=(-pi, -.3), xytext=(pi, -.3),
             arrowprops=dict(arrowstyle='<->', shrinkA=0, shrinkB=0))
 ax.text(0, -.55, '1st Brillouin zone', ha='center')