Dear Nick, I am very grateful for your help. I will follow the tips.
Leone Carmo Garcia 2015-08-18 16:42 GMT-03:00 Nick Papior <[email protected]>: > > > 2015-08-18 19:27 GMT+00:00 leoqmc . <[email protected]>: > >> Dear Nick and transiesta users, >> >> I am interested in transport calculations in single-molecule two-probe >> systems[Au(111)-Molecule-Au(111)]. I searched in the list for the following >> questions, but I think that these questions were not explicitly solved for >> a beginner. Please help me. >> >> 1) Charge: The Molecule is charged(charge +2). Not make sense uses the >> option (NetCharge 2.0) in the transiesta calculation, since that the charge >> will be screened. I'm right? >> > No that will most likely not work, currently this is not an easy task. > >> >> 2) Setup for the electrodes: >> a) The third lattice's vector (z-direction) should have length >> minimal possible, namely it should be enough for the atoms+basis functions. >> I'm right? >> > In your case, make the z-direction periodic. > >> b) The lattice's vectors in x,y direction should include large vacuum >> (~20 Angstroms). I'm right? >> > No, not necessarily, here you can also impose periodicity. Please look at > the examples in the test directory, an example of gold, gold-chain, gold is > shown. That could be the basis for your further geometry creation. See > example ts_au_100, both the repetition and non-repeated structure. > >> c) Usually you use how many units ("N") of the electrodes (N * ABC)? >> > In your 111 direction I would think a single ABC stacking should be > enough. This depends on your basis range, you need to check this your-self. > >> >> 3) Setup for complete device (Electrodes + Molecule): >> >> a) My electrodes are equal. In this case it is mandatory to include >> vacuum in the z direction, such that the device is not affected by their >> image in the calculation of siesta prior to the calculation of transiesta? >> > Please re-read 2a. If electrodes are the same, having a periodic setup is > far better than the alternative. Again refer to the example as suggested in > 2b. > >> >> Thanks in advance. >> >> Leone Carmo Garcia >> > > > > -- > Kind regards Nick >
