Hi,

I have calculated Z2 invariant for a doped Na3Bi semimetal. The node calculation shows that it has 2 Dirac nodes symmetrically placed about G point on the k3 axis at the Fermi energy. So I was expecting Z2 to be non-zero only in the k3 =0 plane. But WT calculation shows that Z2 is also non-zero in the k2=0 and k1=0 planes. Having a nodes on k3 axis implies that k2=0 and k1=0 planes have band touching points and so the corresponding Z2 should have been 0. In fact, for a pure Na3Bi, where two Dirac nodes are on k3 axis I do get expected result (Z2=0 for k1_0 and k2=0 planes), so I am bit confused why I am getting non-zero Z2 for this case. Please let me know if I am interpreting WT results incorrectly.

Thanks,

Fhokrul