Messages

46

General Questions and Answers / Re: Spin Orbit Effect in Graphene

« on: January 24, 2019, 10:37 »

Which version are you using? It is possible to do in the current release, O-2018.06-SP1-1.
If you are experiencing the problem with that version, please share your script and log-file.

47

General Questions and Answers / Re: dft_half_parameters

« on: January 24, 2019, 09:38 »

Right, now I understand. Yes, if you choose "Show defaults" it should be in the basis set definition in all cases. The actual use of DFT-1/2 is governed by the Exchange-Correlation functional, which would be e.g. "GGAHalf.PBE" if DFT-1/2 is used.

I know this is can be a little confusing, but this way of doing it allowed us to provide good element-specific defaults.

48

General Questions and Answers / Re: dft_half_parameters

« on: January 23, 2019, 14:31 »

Please elaborate - it should normally not appear if it is not enabled.

49

General Questions and Answers / Re: how to calculate the band gap of graphene/mos2 heterostructure correctly

« on: January 22, 2019, 15:40 »

The best alternatives are probably DFT-1/2 (same computational cost as GGA) and using PW with HSE06 (for reference calculations).

https://docs.quantumwise.com/tutorials/dft_half_pps/dft_half_pps.html

50

General Questions and Answers / Re: Spin-orbit coupling

« on: January 18, 2019, 13:19 »

This tutorial describes the basic workflow for an SOC calculation, including how to start from a collinear spin-polarized state: https://docs.quantumwise.com/tutorials/spin_orbit_bandstructures/spin_orbit_bandstructures.html

51

General Questions and Answers / Re: Electron Density

« on: January 18, 2019, 13:17 »

No, not on that particular application. You can use the basic workflow from this tutorial which describes molecules on a surface, and then calculate and study the electron density: https://docs.quantumwise.com/tutorials/geometry_optimization/geometry_optimization.html

52

General Questions and Answers / Re: Bulk MoS2 band gap

« on: January 18, 2019, 13:15 »

Could you please explain why you expected 1.2 eV? Is it from a reference where the same computational parameters were used?

Have you converged your calculation with respect to the various computational parameters?

53

General Questions and Answers / Re: Most Stable Configuration

« on: January 18, 2019, 13:11 »

It is fairly introductory, but if you are completely new to QuantumATK, I suggest you start here instead: https://docs.quantumwise.com/tutorials/getting_started.html

54

General Questions and Answers / Re: Interface Builder

« on: January 17, 2019, 15:33 »

The rotation matrix is defined in equation 4 of the paper, and describes how B* is rotated to match up u_1 and v_1 - the strain tensor then describes how the length of the supercell lattice vectors must change, in order to be equal.

55

General Questions and Answers / Re: Interface Builder

« on: January 16, 2019, 08:58 »

It is documented here: https://docs.quantumwise.com/technicalnotes/interface_builder/interface_builder.html

And in the reference paper: http://iopscience.iop.org/article/10.1088/1361-648X/aa66f3/meta

56

General Questions and Answers / Re: Tremolox Potential Editor

« on: January 14, 2019, 09:10 »

The potential editor is really just a more streamlined way of doing the force-field modifications explained here: https://docs.quantumwise.com/tutorials/combining_potentials/combining_potentials.html

The potential components are the different interactions in the constructed force-field. The direct Si-Si interaction could be one example.

57

General Questions and Answers / Re: K-points for bandstructure

« on: January 14, 2019, 09:06 »

Please see the manual apge for a description on how to do that: https://docs.quantumwise.com/manual/Types/Bandstructure/Bandstructure.html

58

General Questions and Answers / Re: Purpose of Electrode Extension ???

« on: January 10, 2019, 13:00 »

Please see our description of the NEGF formalism here: https://docs.quantumwise.com/manual/NEGF.html
You may also consult then introductory tutorial on transport calculations i QuantumATK: https://docs.quantumwise.com/tutorials/atk_transport_calculations/atk_transport_calculations.html

59

General Questions and Answers / Re: anyway to visit the website of quantumwise.com

« on: January 10, 2019, 10:24 »

Put another way: the URL Petr mentions is our new website, so please let us know what you are missing, so we can see if we can add it. We will not re-activate the old site.

60

General Questions and Answers / Re: Most Stable Configuration

« on: January 9, 2019, 09:54 »

A good place to start is probably this tutorial: https://docs.quantumwise.com/tutorials/geometry_optimization/geometry_optimization.html