Messages

61

General Questions and Answers / Re: Relativistic effects like spin orbit coupling

« on: January 4, 2018, 11:36 »

Lot's of spintronics literature considers spin-orbit effects, you may check yourself. I guess there should also be some literature (books, review papers) that discusses the relative impact of spin-orbit coupling in general terms.

62

General Questions and Answers / Re: About the repeatability and correctness of the calculation using ATK

« on: January 4, 2018, 11:34 »

1) By default, the ATK semi-empirical calculators are non-selfconsistent. Try using the Script Generator to switch this to self-consistent (think you can untick a check box to do this).
2) The python script you attach is empty, so I cannot say what the problem is.
3) The website was recently updated, I suggest using the QW documentation website as an entry for the Forum (www.docs.quantumwise.com) or directly use the link https://www.quantumwise.com/forum/

63

General Questions and Answers / Re: Relativistic effects like spin orbit coupling

« on: January 3, 2018, 13:39 »

Very generally (perhaps even overly simplified), spin-orbit effects are important for some types of spintronics calculations, but are most often not important in other kinds of computational research.

64

General Questions and Answers / Re: how to calculate alignment of magnetic moment in electrode in two probe geometry

« on: January 3, 2018, 09:01 »

Sounds like you need to modify the atomic magnetization directions in the Ni electrodes. Use the "Initial State" block for this. See an example here: https://docs.quantumwise.com/tutorials/fe_mgo_fe/fe_mgo_fe.html#anti-parallel-spin

65

General Questions and Answers / Re: antimonene monolayer

« on: January 2, 2018, 15:47 »

Do you have a literature example of such structures?

66

General Questions and Answers / Re: antimonene

« on: January 2, 2018, 15:46 »

Such information is probably available somewhere in literature.

67

General Questions and Answers / Re: Nanowire direction

« on: January 2, 2018, 15:45 »

The Nanowire builder in VNL (Builders -> Nanowire) lets you create nanowires from bulk configurations (e.g. Cu nanowires).

68

General Questions and Answers / Re: Calculation of Dielectric constant of 2-D materials

« on: January 2, 2018, 15:43 »

From a technical standpoint, this is exemplified in a tutorial: https://docs.quantumwise.com/tutorials/optical/optical.html#optical-spectrum. However, from a physical standpoint, I am not sure the Kubo-Greenwood optical spectrum is valid for 2D materials. As far as I know, the KB optical spectrum is mostly applicable to 3D bulks.

69

General Questions and Answers / Re: About the repeatability and correctness of the calculation using ATK

« on: January 2, 2018, 15:39 »

The k/point sampling grid needs to be an instance of the MonkhorstPackGrid module, and then be passed as NumericalAccuracyParameters. I think attached script should work.

70

General Questions and Answers / Re: Space group 57 Pcam

« on: December 15, 2017, 14:00 »

Sorry for the late reply. Looks like the Crystal Builder supports only (pbcm) for space group 57.

71

General Questions and Answers / Re: ZT versus energy

« on: December 15, 2017, 13:50 »

Yes, the x-scale is electron energies measured from the Fermi level.

72

General Questions and Answers / Re: Can not find the "search" button in docs

« on: November 27, 2017, 11:54 »

Perhaps Google search is partially blocked on your end?

73

General Questions and Answers / Re: Can not find the "search" button in docs

« on: November 27, 2017, 09:21 »

Just checked; the search box appears on my PC using both Firefox and Chrome.

74

General Questions and Answers / Re: Can not understand the results by using ghost atom

« on: November 27, 2017, 09:20 »

A ghost atom is nothing but a local basis set positioned some place in space. The DZP/SZP basis set you use is relatively short-ranged (which is sometimes very good), but may not be accurate enough for the study you do. Adding the ghost atom appears to "enlarge" the effective basis set range, which changes your result. I suggest you try to use the default SG15 pseudopotentials and basis sets, which should be both more accurate and longer ranged.

75

General Questions and Answers / Re: Charge Density Plots

« on: November 24, 2017, 07:59 »

The electron density is saved as a 3D Grid. Use the Grid Operations tool to compute the difference between two 3D grids, and plot that difference using either 3D Viewer or the 1D Projector, like done for 3D grids in a tutorial: https://docs.quantumwise.com/tutorials/atk_transport_calculations/atk_transport_calculations.html#voltage-drop