Question on negative s-PDOS

[kaypu]

Dear QuantumWise staff:

In the attachment, the device is composed of carbon nanotube(m=n=4) and anthracene (certral molecule). all the device has been optmized using LBFGS(z vetor is not fixed).The corresponding script is also in the attachment. The self-energy is chosen recursionself energy to avoid negative transmission appearing. Integral lower bound is set to 4.0 hartree to  eliminate charge missing problem.

but there are still some problem...

in the s-PDOS.jpg, near -1 eV, the PDOS of s state is negative, is that right? could  you help me to figure out this problem?

                                             Thanks

[Anders Blom]

Well, there is really just one single point on the graph that is negative, so it has no real physical significance, it's just a numerical artifact.

The device is generally very short, the electrodes need to be at least 2x longer in Z.