Recent Posts

31

General Questions and Answers / Re: Unit trouble dipole moments

« Last post by MariaWJ on May 1, 2024, 09:39 »

So the final unit should then be bohr*e, great. I am actually using electron difference density with a script adapted from your tutorial, but thanks for the heads up. I have a final curious question, would this dipole approach actually be applicable for periodic boundary conditions or is this purely molecular?
I am trying to calculate both polarization using the dipole for a monolayer with a bias. The bias I create with the metal plates but the dipole and  seem to respond rather drastically yielding too high values, so I just wondered if maybe I shouldn't do dipole with periodic boundaries?

Hope you have some insight

32

General Questions and Answers / Re: Unit trouble dipole moments

« Last post by Anders Blom on April 30, 2024, 20:28 »

Yes, it's a mistake. At some point in the ancient past numpy.dot would strip off the unit so we had to reapply now, but now it gets multiplied in with the unit already applied.

Just skip the length_unit**3 and it works better! However, also see https://forum.quantumatk.com/index.php?topic=10790 about why you should use the ElectronDifferenceDensity, rather.

33

General Questions and Answers / Re: Phonon dispersion is senstitive to "processes_per_displacement" paramter of DM?

« Last post by Anders Blom on April 30, 2024, 20:19 »

Aha, interesting... I'll make sure to forward this to our developers, however at least now you have a workable way to run the calculations fast, and correctly!

34

General Questions and Answers / Unit trouble dipole moments

« Last post by MariaWJ on April 30, 2024, 14:06 »

Using the script for calculating dipole moments seems to have an error in the unit. I follow the tutorial: https://docs.quantumatk.com/manual/Types/ElectronDensity/ElectronDensity.html . What is the correct unit for the dipole moment?

I think the problem is this line:
# Calculate the volume of the volume element.
dV = numpy.dot(dX, numpy.cross(dY,dZ)) * length_unit**3

When I print dV.unit() I get bohr**6, I assume that is a mistake.
So is the final dipole printed in the unit of e*bohr or is it maybe Debye? or am I misunderstanding something?

Please help me, I am very confused!

35

General Questions and Answers / Re: Phonon dispersion is senstitive to "processes_per_displacement" paramter of DM?

« Last post by krabidix on April 30, 2024, 07:59 »

With '24' and '4' cores, the results match.

36

General Questions and Answers / Re: X-Ray scattering of MD trajectory

« Last post by tafa11 on April 29, 2024, 21:53 »

Thank you, it works now,  apparently I was using an old version!

37

General Questions and Answers / Re: X-Ray scattering of MD trajectory

« Last post by Anders Blom on April 29, 2024, 18:59 »

It is, at least in the newest version that I use (2023.12-SP1), but I think it's been there for quite some time.

38

General Questions and Answers / Re: Building type 1, 2, 3 quaternary heusler alloy

« Last post by Anders Blom on April 29, 2024, 18:54 »

There is a quite clear discussion on this in https://arxiv.org/pdf/1903.07265 for Y, L2_1 and B2.

I believe D0_3 is not a quaternary structure, but rather binary, of the type V3Si?

39

General Questions and Answers / Re: Building type 1, 2, 3 quaternary heusler alloy

« Last post by physics on April 29, 2024, 14:41 »

Hi,

Thank you for your reply. I want to know how to build quaternary heusler alloy of Y, L2, B2 and D0 type.

Thank you

40

General Questions and Answers / Re: X-Ray scattering of MD trajectory

« Last post by tafa11 on April 27, 2024, 04:58 »

Thanks for the response, I saw what the manual says and was under the impression that X-Ray scattering is one of the analysis options under MD analyzer but it is not, is there something I am missing?