Author Topic: The construction of a two-dimensional material  (Read 128 times)

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Offline Bertha_He

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The construction of a two-dimensional material
« on: August 9, 2019, 05:56 »
Dear experts,
      I am using the 2016.04 version of ATK to build a two-dimensional material that is not in the material library.
Now I have some problems and need your help.
I consulted the literature and constructed this two-dimensional material according to the method in the case guide
(https://docs.quantumwise.com/tutorials/opening_a_band_gap/opening_a_band_gap.html).
After the structure optimization, I get lattice constants similar to those in the references, but there is no bond between atoms.
After trying, I found that when I changed Graphics-property-Fuzz factor in the Builder, keys would appear between the atoms
when the default parameter 1.10 in the Fuzz factor was changed to 1.15.
There's another case, when I change the value of KA in the K sample in New Calculator, when the value of KA is fixed to a value, the atoms will bond;
When you change KA to something else, there are no bonds between the atoms and the lattice constant changes´╝Ť
The lattice constant will be fixed to other values, but this value will be quite different from the value in the literature.
I wonder why? How do I deal with this situation?
Is it reliable to change the keys of Fuzz factor?Can I use this model for that?

 Thanks

Offline Jess Wellendorff

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Re: The construction of a two-dimensional material
« Reply #1 on: August 12, 2019, 15:23 »
Dear Bertha,
the fuzz factor simply determines how close two atoms must be in order for the GUI to draw a bond between them, so it is safe to tune it a bit according to chemical intuition. As for the k-point sampling along direction A, the equilibrium lattice constant should converge to a constant value as k_A increases, so you should probably check that.