Questions tagged [2d-lattice]
For questions related to 2-dimensional materials which are periodic, i.e. crystalline.
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How to Create a 2D Structure of Boron (Brophene) using ASE?
Unlike Graphene and MoS2, For borophene, I didn't find any inbuilt function in ASE. I have tried to make it, but i failed. So If anyone could help me, it will be great help.
Since brophene has ...
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Packages that can model effects of intense electric fields from femtosecond compressed IR and EUV laser pulses on surfaces?
Laser-based and time-resolved ARPES are relatively1 new techniques to study atomic and especially electronic structure (necessarily) near crystal surfaces and of adsorbed 2D materials on those ...
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How to find the scaling factors for minimum image convention?
Suppose that we have an arbitrary (not necessarily cubic) unit cell with cell parameters $\mathbf{a}$, $\mathbf{b}$, $\mathbf{c}$ (lattice vectors) and $\alpha$, $\beta$, $\gamma$ (lattice angles).
We ...
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Compute band energies with respect to the vacuum level with QE
I want to calculate the band energies of a 2D material with respect to the vacuum level to normalize my band energies with Quantum Espresso. I found a post here, which was not really satisfying for me....
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Are lattice-based Monte Carlo simulations used in the case of liquids and gases?
The Ising model uses a lattice-based model as it is reasonable to simulate magnetic behavior in a solid.
Is lattice-based Monte Carlo modeling used in the case of the simulation of gases and liquids (...
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How to perform carrier doping (hole/electron) for 2D materials by Quantum Espresso?
I tried to set the tot_charge parameter of Quantum Espresso to alter the charge of the system, but the phonon spectrum I obtained was very strange. Could anyone ...
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1
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Modelling 2D semiconductor heterostructures including one magnetic layer with QE
I want to compute the electronic structure of a heterostructure composed of two 2D monolayers. I am stacking a TMD monolayer on top of a magnetic 2D monolayer. Both of them are semiconductors.
Do I ...
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Weighted average optical spectra in VASP
I am working on a 2D system where geometric and magnetic isomers are energetically very close to each other (orders of meV). I am interested in optical absorbance spectra using GW+BSE approach but I ...
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VASPKIT and SeeK-path recommend different paths. Which one to choose?
I want to get the phonon density of states for a monolayer MoS2. For this, I need phonon dispersion curves, and to choose a path where to compute phonons.
VASPKIT recommends Γ-M-K-Γ
SeeK-path ...
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1
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A cubic unit cell in DFT of volume 'V' has 'n' atoms in it, for an extended volume V' how many atoms would be there in the new volume?
We can also assume the lattice parameter of the cubic unit cell to be a and the that of the extended cell to be a', which means that V' = (a')^3
So is the number of atoms n' in the extended volume V' ...
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How to query 2D materials on materials project?
I would like to use the materials project API to search materials with some properties but to restrict my search only to two-dimensional materials.
How to do it?
Web-pages for materials contain the '...
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answer
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How to stack graphene and hBN on top of each other?
I read in papers (e.g. link) about AA stacking, where C atoms are above the B and N atoms, and AB stacking where one C atom is above the N or B atom, while the other C atom is above the h-BN hexagon.
...
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2D mass spring system approach for pump-probe experiment modelling
I am working on a pump-probe reflectivity experiment and wanted to try my hand at some modelling. This is my first time doing this and I have a somewhat working, but buggy Matlab script that kind of ...
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LAMMPS calculated graphene thermal conductivity lower than expected
I have been trying to calculate the thermal conductivity of a square graphene sheet of 3200 atoms, but I get a k value of 150W/mK, which is many times smaller than the published 4000W/mK. I am fairly ...
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Molecular dynamics method to simulate a simple fluid
I need to implement the molecular dynamics method to simulate a simple fluid that interacts through the Lennard-Jones potential in a 2D simulation. The idea is to explore how the total energy of the ...
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1
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3D band structure plot
I am trying to plot 3D band structure of my system of interest. I have used Quantum Espresso software for calculating the band structure and plotted 2D band diagram. But from here I am unable to ...
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How to construct thin film structure of desired thickness in quantum espresso?
I want to study the properties of thin films using DFT calculation. I have done the bulk crystal calculations in Quantum ESPRESSO but have no idea how can I construct the thin film of desired ...
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When to use pseudohydrogens to passivate a slab?
I often see some papers that don't use pseudohydrogen passivating the slab's bottom side when doing DFT simulation on the metal oxide's surface, for example, the following description is from a paper ...
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Optical properties without LOPTICS tag
I have performed some calculations for a 2D-monolayer using VASP.
I run DOS calculations without LOPTICS = .TRUE.
I found that ...
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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 $\...
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Straightforward formalism to get sets of lattice vectors of fcc (111), (110) and (100) facet surfaces that I can also cite?
I am simulating low energy electron diffraction (LEED) from a polyfaceted sample. Usually it's a single, well-defined flat crystalline surface.
Since low energy electrons (below a few hundred eV) only ...
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POSCAR data file for a 2D system
I would like to understand how to calculate the band structure of the Graphene monolayer system using DFT. I am using VASP for material simulation. My question is how to write the crystal structure ...
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How to determine the more stable configuration between a flat and a buckled monolayer with DFT?
Using first principles methods (quantum espresso code) I would like to find if a monolayer of a material is flat or buckled. Using the van der Waals interaction in the calculation I found that the ...
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What's the past and future of 2D materials since graphene?
Since the discovery of graphene in 2004, two-dimensional (2D) materials have been a hot topic in the community of condensed matter physics, which can be considered as the candidate for next-generation ...
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How can I prove that a material is ferroelectric using DFT?
I would like to prove that a 2D material (Say ZnO) is ferroelectric. Since Ferroelectric materials are a subset of piezoelectric materials. How should I proceed to prove that the polarization is ...
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How to separate the band structure of different materials in heterostructures using Quantum ESPRESSO?
So, I know that to calculate surface band structure of a material, you have to take its 2D system eg. single or few-layered. But, how to find the surface band structure in the case of heterostructures....
- 1,561
9
votes
1
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Quantum ESPRESSO: parameter "assume_isolated": is it applicable to slabs?
I am studying atomic slabs which are periodic in 2 dimensions. Normally in the third dimension, I add a vacuum layer and use dipole correction to mimic proper boundary conditions. Recently I have ...
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3
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When do I use the lattice parameters obtained computationally vs experimentally?
I have been trying to simulate the properties of Bi2Se3. But the lattice parameters given in Materials Project (which I believe is obtained computationally) is inconsistent with that of experimental ...
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How to derive the k-path for monoclinic lattice structure?
Good afternoon all,
My post is inquiring about the mathematical derivation behind the Monoclinic crystal structure (c axis unique).
The Brillouin zone (BZ) I really would like to derive is shown below:...
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answer
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Physical origin for higher bandgaps when going from bulk to few-layers
This is a trend that's observed in most materials that I've observed. When you go from bulk to monolayer, the bandgap of the material increases: this is true for commonly studied materials like ...
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Why is VASP so popular for 2D materials?
I have seen that in many articles of 2D materials calculations that VASP is the most used one among DFT codes. Could please explain to me why?
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Inversion symmetry in 2D materials
Transition metal dichalcogenides (TMDs) are composed of three atomic planes and often two atomic species: a metal and two chalcogens. The honeycomb, hexagonal lattice has three fold symmetry and can ...
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Berry's curvature and magnetic moment in TMDCs
I am studying the transition metal dichalcogenides (TMDCs) and one of the applications that these materials have is their use in valleytronics. Valleytronics is related to the magnetic moment, Berry ...
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answer
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Why can't I reproduce the behavior of an H-saturated graphene flake?
I'm trying to simulate a graphene flake with its edge C atoms saturated by H atoms, in a temperature ramp from 300 K to 1600 K, using LAMMPS and the AIREBO potential proposed by Stuart et al. in 2000.
...
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2D Brillouin zone generator
There are several pages where you can find scripts/simulations to generate the first Brillouin zone for square and hexagonal 2D lattices.
I wonder if there is a tool to generate the Brillouin for ...
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