# Tag Info

13

I designed the Python program a few years back but haven't looked at it in some time. The __init__.py line can be commented out for your usage. That "model" was for my team's use case, and it looks like I got rid of it. You may be better off importing the "material_analytics.py" directly, and using those functions right on your dataset. ...

12

I was able to run the code on your data and got a Young's Modulus of $2.08236\times10^{-5}$. This clearly doesn't seem right for an aluminum system, though I don't know the units you are using. To get this, I had to make a few changes to both the code and your data. As suggested, by Enusi, I commented out from model import stress_strain from the __init__.py ...

11

If you have already obtained satisfactory convergence with a (relatively) sparse k-point grid, there is no motivation to go for a denser grid. So if you have already achieved convergence with 12x12x4, there's no need to go to 12x12x12. If you are talking about graphene, which is 2-D, there is no need to sample points along the out-of-plane direction. There ...

11

Basis set name versus number of total orbitals I would like to first address a part of the question that appears to be a misconception about the use of a 6-31+G(d,p) basis set, since you wrote: "In my understanding of such basis sets, it is difficult to do this." 6-31+G(d,p) is not a "big" or "small" basis set, unless we're ...

9

I agree with the answer provided by Xivi76. I just wanted to add that some codes have a very nice functionality that facilitates convergence: rather than explicitly writing out a $\mathbf{k}$-point grid $n_1\times n_2\times n_3$, in which in principle you have to converge three values; you can instead specify a $\mathbf{k}$-point spacing or density, in which ...

7

As far as my knowledge this a relationship between k-points and lattice constants values. I'll give you an example of a layered hexagonal material WS2: Lattice constants : a=3.17 b=3.17 c=12.41 ; so c/a = 12.41/3.17=3.91 K-points : If I chose kx=12, ky will be equal to 12 but kz should be equal to an integer close to the kx divided by c/a. I mean kz=12/3.91=...

6

I will try to give the most practical answer, the reality of "is this converged" is that you cannot know without checking by going past it. You say that you would like to save time doing these calculations, but the worst loss of time is sometimes the loss of your own human time as you get confusing results later. I am unsure how you came to the ...

5

I have got your calculation successfully completed: The final electronic energy is -0.928161992153724 a.u. This computation required 318.38 seconds (walltime). My output (and input) files are here. They are the same as yours, except my ZMAT uses my basis set database, which I don't think will make a difference for you,...

2

Unfortunately, due to my reputation, I cannot comment yet. However, to the surprise of Typerius, I would like to note that the function young_modulus does not return the Young's modulus, but the compliance. The code looks as follows return (lin_elastic_region[-1,1],lin_elastic_region[0,1])/(lin_elastic_region[-1,0]-lin_elastic_region[0,0]) with ...

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