Questions tagged [defects]

For questions about modeling material defects (e.g. vacancies, interstitial/substitutional impurities, topological defects).

Filter by
Sorted by
Tagged with
3 votes
1 answer

How to determine defect charge state degeneracies?

I am doing defect calculations using the SC-FERMI package. However, one of the inputs is the degeneracy of the charge states of each defect. I know degeneracy is the number of states with the same ...
  • 223
4 votes
2 answers

Which formalism is better suited to model a crystal with defects: Hartree–Fock, Kohn–Sham, or something else?

Let’s suppose that (1) it’s required to calculate a crystal with certain parameters of a crystal lattice; (2) this crystal has some defects (let it be Frenkel defects for simplicity); (3) these ...
  • 549
4 votes
1 answer

Decide the position of oxygen vacancy via the configuration with the lowest energy?

I am trying to determine the position of oxygen vacancy in $\ce{TiO2}$, is it reasonable to decide it by choosing the configuration with the lowest energy? It doesn't feel quite right to always choose ...
  • 1,885
8 votes
0 answers

How to distinguish between deformation mechanisms in creep experiment? [closed]

As I'm learning more about viscoelasticity and creep experiments, I'm trying to understand how to distinguish between the different deformation mechanisms. In general, when a sample of viscoelastic ...
9 votes
0 answers

Difference of high-frequency and static dielectric constants? [closed]

I found in an article [1] the following definition of FNV (Freysoldt, Neugebauer and Van de Walle) energy correction term for a charged defect in a cubic supercell: $$E_{\text{corr}}=\frac{\alpha_Mq^2}...
7 votes
1 answer

Relax vs VC-Relax for interstitial incorporation energy

In order to model an interstitial trapped in a metal lattice, and the associated incorporation energy, which should be used - "relax" or "vc-relax"? I want to understand the ...
  • 457
11 votes
1 answer

How to start with structural defects in monolayer?

First of all, thank you for your help! You are so helpful every time. I would like to calculate the influence of the structural defects on the electronic structure in the HfS2 monolayer. With VESTA ...
23 votes
0 answers

What are the tools available for point defects calculations? [closed]

It would be appreciated if you could explain one of the tools below (or another tool not listed), in the format used here (for example): What software will allow me to combine two images? What ...
  • 491
15 votes
1 answer

What are good resources to study crystallographic defects in different dimensional systems and their topological dimensionality?

I wonder if there are any books or resources that may address one or more of the following questions: What kinds of defects are important for topology? Especially crystallographic defects. How do ...
18 votes
1 answer

What are some approaches to modeling charged point defects in materials?

From what I understand, one major issue in modeling charged point defects in materials is the existence of artificial interactions between charged defects and their periodic images. Even when using ...