Questions tagged [supercell]
The supercell tag has no usage guidance.
11
questions
9
votes
0answers
42 views
Difference of high-frequency and static dielectric constants?
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
1answer
127 views
Help understanding square root notation of supercell
I often see supercells and slabs explained like this:
$2\sqrt{2} \times 6$ slab of $\ce{MoS2}$ (001)
$\sqrt{2} \times \sqrt{2} \times 2$ supercell of $\ce{Y Ba(1−x)Sr(x)CuFeO5}$ (see here).
Take $\...
8
votes
0answers
64 views
Crystallography: How to sample *unique* structures from configuration space? (binary alloy supercell)
I'm working with a binary alloy system (call it 'AB'), and I'd like to generate a few unique configurations for DFT purposes.
My primitive cubic unit cell consists of 4 atoms; i.e. 4 positions. Thus, ...
3
votes
1answer
58 views
How to make left and right handed material interface using python
I have a crystal structure, a B20 compound. I want to make an interface of that bulk compound with left and right-hand material. Is there any python code for writing such interfaces. or for writing ...
5
votes
1answer
116 views
Supercell model for a disordered system in phonon calculations using the harmonic approximation
I studied a disordered state (FCC solid solution) and used a special quasirandom structure supercell with 32 atoms to represent the system. After relaxing it thoroughly with ...
12
votes
2answers
261 views
How to sort a supercell for a molecular crystal?
I am trying to build a supercell of the following (below) molecular crystal from its .cif file. How do I sort a supercell here according to each molecule in the supercell? I'm not tethered to a ...
5
votes
1answer
156 views
ASE: why do I get warnings about "monoclinic" and "orthorhombic" not being interpreted?
I am trying to use ASE (Atomic Simulation Environment) to build a supercell of some molecular crystals and then output the result to a file with the atoms given in a specified order for each molecule, ...
7
votes
1answer
105 views
Using LAMMPS for a small system
I want to run a classical molecular dynamics simulation on silicane using LAMMPS. Since I don't have access to any HPC nor do I have a powerful desktop PC, I'm planning on making the system small. By ...
8
votes
2answers
202 views
Extracting the coordinates of a super cell in Vesta or Avogadro
I am trying to use a program such as Vesta or Avogadro to build a super cell from a .cif file for a molecular crystal. In neither program can I seem to figure out how to order the output of the ...
4
votes
2answers
106 views
Energy per unit cell in NWChem differs for different supercells despite the same k-points density
I try to compute the unit cell energy of the $\ce{Ti2CO2}$ MXene with NWchem.
Computing the 1x1 supercell with 4x4x1 K-points grid I got -1875 Ha.
Computing the 2x2 supercell with 2x2x1 K-points grid ...
7
votes
2answers
214 views
What is the meaning of the "PRIMCELL.vasp" file generated by VASPKIT tool during bandstructure inputs generation?
When I use VASPKIT tool to generate K-path KPOINTS file for Bandstructure calcualtion of a 4x4x1 supercell of a pure material, ...
