Is it possible to set up an N-electrode system in TranSIESTA?
Yes. The optimized tbtrans code enables multiple electrodes in the DFT+NEGF code TranSIESTA.
There are examples in the Tests/TranSiesta-TBTrans folder with three and four electrodes. Please consult these examples for directions on how to set up other N-electrode systems.
Other improvements on non-equilibrium and transport Green function techniques are described here (https://www.sciencedirect.com/science/article/pii/S001046551630306X)