Questions tagged [physical-properties-of-materials]
Questions about modeling or theoretical/computational values for physical properties of materials such as ductility, Young's modulus, malleability, conductivity, specific heat capacity, density, etc.
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Number of electrons per cell
I aim to do a HF-like calculation on a 2D graphene layer. What is the number of electrons per cell?
Edit: There are six carbon atoms per cell.
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Are then any material property solvers (from Charge Density) available in python?
I am looking to predict properties like the Bulk Modulus, total energy, etc., all from the charge density I have as input (CHGCAR file)
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How to go from zero to hero in Machine Learning for materials modelling
I am interested in exploring the use of machine learning tools to accelerate molecular dynamics simulation probably by training machine learning potentials. While I have found some papers that apply ...
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Database on calculated molecular vibrations including coordination complexes?
Related to the question Are there dashboards displaying experimental properties of molecular materials?
My question is: Are there any good, free, online databases on calculated vibrational modes of ...
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Calculating bulk modulus of aluminum using pymatgen and MLIP
I have an interatomic potential (CHGNet) which is interfaced with pymatgen and can output the stress on any structure. Now, I want to use pymatgen to calculate the bulk modulus for aluminum. The code ...
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Explicit calculation of Poisson's ratio using energies from a potential energy surface [closed]
I would like to calculate the above quantities for a given unit cell (or supercell) with arbitrary symmetry. Specifically, I am trying to use a machine-learned interatomic potential (MLIP), and since ...
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How can I calculate the elastic properties of a unit cell and a supercell?
Can someone please share with me a method to compute the elastic constants of the unit cell and doped supercell of a material?
In my calculation I use Quantum ESPRESSO. And I already tried Thermo_pw, ...
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Query about NiO structure
I have one query about the NiO structure. As per the literature, NiO is a rocksalt type of structure ( NaCl type) and exhibits an antiferromagnetic ordering of type-II cubic (fcc). I considered the ...
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why can a defect have a lower barrier strength compared with another defect but still have a larger effect on embrittlement? [closed]
I have read that for a particular alloy system, a specific precipitate has a low barrier strength to plastic deformation in comparison to dislocation loops. However this precipitate gives the largest ...
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How to Find the Huang-Rhys factor from the Intensity Vs Wavelength plot (PL plot)?
How can I find the HR factor like we calculate the Debye waller factor as - log(IZpl/Itotal), from the intensity profile of the PL spectra.
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Calculating theoretical density from .cif files
I'm studying structure-property relations in MOFs and have a pool of hypothetical structures in .cif format generated using ToBaCCo code. I want to filter them based on theoretical density, but the &...
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Noob Question: How can I write bulk, monolayer and bilayer structure in input file for visualizing it
I'm getting my bachelor degree in physics and in my structure of matter course we never talked about bulk, monolayer and so on. I can understand Bravais lattice , reciprocal lattice and so on but I'm ...
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Is there any effect on the physical properties when the size of the system increases in DFT?
I am using Quantum ESPRESSO to do some DFT calculations. I want to know if the optoelectronic properties obtained by a unit cell would remain the same when the properties are obtained by using a ...
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What is the best method to compute crystal structures?
I am rather new to VASP and I have seen people using different methods to compute crystal structure:
Using Birch-Murnaghan equation to find optimal lattice volume, and then adjust the structure ...
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Why is strain rate used instead of absolute strain for modelling stress relaxation of a viscoelastic material using the Maxwell model?
I don't quite fully understand the derivation of the Maxwell model for prediction of stress relaxation for viscoelstic materials. usually the governing equation can be described in terms of strain ...
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What determines if a material tends to undergo transgranular or intergranular fracure? [closed]
As an example, why does glass tend to break by means of intergranular fracture?
My analysis so far led me to believe that the tendency can be related to the intermolecular bond strength in a given ...
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What's the meaning of k-points with weight zero?
In a post from the Quantum Espresso mailing list, a user suggests adding k-points with weight zero to an SCF calculation as a workaround to allow bandstructure to be computed using a hybrid functional....
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How to calculate lattice parameter?
After 'vc-relax' calculation I got the cell parameters in the picture bellow. I want to mention that my ibrav=1.
I think the optimized lattice parameter in this case is A=11.44879234*1.006676454 .But ...
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How to implement Ueff=U−J in a Quantum ESPRESSO input file? [closed]
I want to implement Ueff=U−J in a Quantum ESPRESSO input file, but I don't know how to do that.
I found the following on the internet:
...
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Do I have to repeat my previous calculations after increasing 'diago_david_ndir' in the input file of the bandstructure calculations? [closed]
After doing the convergence test, 'vc-relax' and 'scf' calculations for my material using Quantum ESPRESSO everything went well. But when I wanted to do a 'bands' calculation for bandstructure I got ...
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Are the cell parameters found after doing a 'vc-relax' calculation the ones used to calculate the material properties?
I created a CIF file using the experimental data from literature . After doing a 'vc-relax' calculation do I have to change the lattice parameter, CELL_PARAMETERS and ATOMIC_POSITIONS in my input file,...
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Reference textbooks for calculating pressures/stress/strain/tensors?
Is there a good reference textbook for calculating pressures/stress/strain/tensors in materials - vapor, liquids and solids? Pure physics is fine, but it would be a bonus if it also included force-...
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How to Model Antiferromagnetic NiO p-type semiconductor?
I'm a beginner in DFT and I want to study the properties of NiO and doped-NiO materials using Quantum ESPRESSO.I found in the internet that I should introduce the spin magnetization in the Input file (...
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Software recommendations to construct band structures using tight binding
I am at the beginning of computational materials modeling.
My objective is to calculate the electrical conductivity of a system that consists of several thousand atoms, and running DFT calculations is ...
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Bending rigidity of the nanomaterial from MD simulation
The literature seems to be very diverse in measuring the bending rigidity of the nanomaterial from MD simulation. I have seen people often use this relation from continuum mechanics $$k = \frac{Eh^3}{...
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Calculation of quantum capacitance for materials using Quantum Espresso [closed]
I wish to run DFT calculations on Quantum Espresso for the calculation of quantum capacitance. I have gone through literature, specifically, "Graphitic carbon nitride decorated with FeNi3 ...
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Software for Molecular Dynamics in Material Science
I would like to know available software that can do Molecular Dynamics (MD) simulations for any type of system, specifically inorganic and organic ones.
The must cited MD packages (GROMACS, AMBER, ...
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Is there a way to estimate the energy of desorption of an adsorbed molecule? [closed]
I'm studying the adsorption of several molecules in metal organic frameworks (MOFs) using both experimental and computational methods. Experimetally I can easily obtain the temperature at which a ...
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Difference between "electrical" and "electronic"?
I found that people often measure "electrical conductivity", but some may say "electronic conductivity". Can anyone explain the terms "electrical" and "electronic&...
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Elastic constants calculation
I am doing elastic calculations using VASP code in which
OUTCAR contains four different elastic moduli: ELASTIC MODULI , ...
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Spacing issues about multiple-layer bcc structure
I am trying to make Hartree potential of bcc Tungsten(001).
My software is VASP.
5-layer should have 5 bound states.
But I don't have them
I heard it is a layer-layer spacing issue.
I built slab of ...
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study of elastic properties under pressure using VASP [closed]
I want to replicate this paper, but somehow I cannot get the same results, most important as shown in table 2. Can anyone help me with this?
I have attached the INCAR file. If any correction is needed,...
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How to map high symmetry points from primitive cell to conventional cell?
We usually plot electronic bands with the help of high symmetry points of the irreducible zone of primitive cell of particular material. But if we want to plot bands with conventional cell, we have to ...
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Analytical derivative method in ab initio molecular properties calculations
In order to relate results from quantum chemical calculations to experiment, it
is essential to compute quantities that are directly available from measurements.
Properties describe the "response&...
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Predicting the band gap or some other properties of materials before running any calculations
Can we some how predict what sort of modulation will doping do to a material without actually running any calculations. Like perhaps we use the already known DOS of Zn in order to predict whether the ...
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How to estimate chemical potential at a temperature?
Fermi level is electron chemical potential at 0K and we can obtain it from DFT calculation. However, the chemical potential is dependent on temperature. But I only find the equation for gas or simple ...
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Recommendation for some papers on simulation of metallic metal
I want to simulate the collision between two gas giants, the inner layer of gas giant contains the layer of metallic hydrogen and a solid core, if two gas giants collide then the abrubt variation of ...
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Examples of anti-symmetric rank-3/4 tensors?
The anti-symmetric rank-3 and rank-4 tensors hold the following properties:
\begin{align}
\sigma_{mnk} &=-\sigma_{nmk} \\
\sigma_{mnkp} &=-\sigma_{nmkp}
\end{align}
Note I'm using ...
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Cohesive energy of Cu with Quantum Espresso
Using this input
Cu FCC vc-relax method error
to calculate Ebulk, I'm trying to calculate the cohesive energy of solid Cu (Ecoh = Eatom − Ebulk). For the Eatom I'm using a similar input but with '
<...
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What is the difference between elastic and mechanical properties of materials?
I have seen many articles[1] that write in the title "mechanical properties of ...", but in the subsections of the paper, they write "elastic properties" and discuss elastic ...
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Why is there a deviation between the experimentally calculated values and theoretical done by DFT calculation? [duplicate]
If there was a deviation between the experimentally calculated values and theoretical determination done by DFT calculation, then what is the reason?
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Are there tools to calculate the electrical conductivity of large (>1000 atom) nanostructures?
Are there any free to use tools which can be used to calculate the electrical conductivity of nanostructured materials. The systems that I am interested in consist of several thousand atoms, and ...
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How to find the Cauchy stress tensor in solids using ab-initio methods?
I want to find the Cauchy stress tensor in certain materials with ab initio methods. I already have the analytical form of my own definition of "energy" and "forces" (not from DFT),...
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About LaCrO3 space group stability
I found two space groups of $\ce{LaCrO3}$ material Pnma and Pm-3m. If someone is familiar with this material, please help to understand which phase is more stable. what are the factors that determine ...
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Compute bulk electrical conducitivity from single-crystal measurements [closed]
If I have single-crystal measurements of electrical conductivity along 3D axes (considering for example anisotropic materials), is there any straightforward way to compute the bulk (global) electrical ...
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Why do some decanters dry quickly, and others dry slowly?
My decanters are washed in hot water. The outside is then dried with a clean cloth, as is the top of the inside of the neck — typically one can’t reach further. The still-warm decanter is then left ...
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Viscosity calculation using molecular dynamics simulations
I use the GROMACS software for MD simulations and I am trying to understand the calculation of viscosity using combinations of different ensembles and different methods.
For a non-equilibrium MD ...
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Linear combination of homogenized composite material [closed]
My research is on the structural optimization of fibre-reinforced composite material (transversely isotropic material). I am currently working on a homogenization method for attaining the effective ...
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Calculating lattice thermal conductivity using Quantum ESPRESSO and phonopy
How should I calculate lattice thermal conductivity in Quantum ESPRESSO? I have installed phonopy. My Linux distribution is Ubuntu.
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Large dataset with conductivities of materials and chemical compounds? [closed]
I'm looking for a fairly large (>100k) dataset of chemical compounds (and materials) that has conductivities. I've looked at PubMed, but couldn't find conductivities.
I would ideally like to avoid ...
