If \( a \in \mathbb{R} \) and the equation \( -3(x-[x])^{2}+2(x-[x])+a^{2}=0 \) (where \([x]\) denotes the greatest integer \(\leq x\)) has no integral solution but has real solutions, then all possible values of \(a\) lie in the interval:
1
\( \left ( -1,0 \right )\cup \left ( 0,1 \right ) \)
2
\( \left ( 1,2 \right ) \)
3
\( \left ( -2,-1 \right ) \)
4
\( \left ( -\infty ,-2 \right )\cup \left ( 2,\infty \right ) \)