2015-08-20 14:14 GMT+02:00 leoqmc . <[email protected]>: > Dear Nick, > > I read the paper you recommended. The author recommends adding more > electrode atoms in the transversal direction in order to reduce the > effect of interference due to device images. My question: > > 1) What is the problem in adding vacuum in the transverse directions? I > think it would reduce the effect of interference due to device images. > Yes, sure you would remove the interference, but it would not be a bulk (periodic) electrode, rather it would be an electrode "chain".
> > > Since already very Thank you. > > Leone Carmo Garcia > > > > 2015-08-19 14:51 GMT-03:00 leoqmc . <[email protected]>: > >> Dear Nick, >> >> Thank you. I'll read the paper. >> >> Leone Carmo Garcia >> >> 2015-08-19 14:36 GMT-03:00 Nick Papior <[email protected]>: >> >>> >>> >>> 2015-08-19 17:14 GMT+00:00 leoqmc . <[email protected]>: >>> >>>> Dear Nick, >>>> >>>> I prepared my inputs following your tips and test inputs. I'm waiting >>>> for the calculations to complete. But one question remains. >>>> >>>> 1) I want to get the transport properties in a single molecule and not >>>> added vacuum in either direction (as the tests that you recommended). The >>>> results will not be influenced by the "images" of my device? >>>> >>> Sure they will. :) >>> >>>> >>>> >>>> 2) I have seen examples that use large vacuum in the x and y directions >>>> . When this is recommended? >>>> >>> This is a drawback of the supercell approach, however, please look >>> through litterature for this. >>> This article touches upon that: 10.1103/PhysRevB.72.033401, as well as >>> how to circumvent 1). >>> >>>> >>>> >>>> From already thank you very much. >>>> >>>> Leone Carmo Garcia >>>> >>>> 2015-08-19 8:47 GMT-03:00 leoqmc . <[email protected]>: >>>> >>>>> 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 >>>>>> >>>>> >>>>> >>>> >>> >>> >>> -- >>> Kind regards Nick >>> >> >> > -- Kind regards Nick
