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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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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6 votes
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73 views

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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3 votes
0 answers
62 views

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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3 votes
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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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6 votes
1 answer
92 views

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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6 votes
1 answer
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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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3 votes
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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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6 votes
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70 views

Are there tools to calculate the electrical conductivity of 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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  • 2,454
9 votes
1 answer
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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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  • 193
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1 answer
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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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6 votes
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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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4 votes
1 answer
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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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7 votes
1 answer
185 views

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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5 votes
0 answers
32 views

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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9 votes
1 answer
189 views

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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10 votes
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94 views

Large dataset with conductivities of materials and chemical compounds?

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 ...
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9 votes
0 answers
82 views

How to calculate the thickness of the slab when simulating a bulk surface? [closed]

The method I found, which seems to be the most commonly used for simulating surfaces, involves constructing a slab and doing a structural optimization by freezing a few of its lowermost layers. What ...
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8 votes
2 answers
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Mathematical models for the plastic region in the tensile test

The tensile test of a material consists of subjecting a standardized specimen to an increasing axial tensile stress until it breaks. During its performance in the laboratory, we can plot a stress-...
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9 votes
0 answers
95 views

Is "Valence Electron Density" and "Electron Density" data of a molecule the same thing? [closed]

I'm wondering specifically in the context of calculating physical properties from valence-electron-density data using DFT, MD, and or ML (machine learning).
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18 votes
3 answers
278 views

Are there dashboards displaying experimental properties of molecular materials?

A dataset is generally a collection of data. A database is an organized collection of data, allowing different kinds of queries. A dashboard is a graphical user interface that is employed to make ...
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9 votes
1 answer
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Why VASP calculates the elastic constant for another trigonal space group?

Please, help me to understand the problem. I calculated the elastic constants for the beta PHB (Space group P3221 (154)), it has to show the reduced elastic constant matrix (six), however, ...
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  • 191
8 votes
1 answer
129 views

How to calculate the volumetric energy density of a molecule?

I am trying to store hydrogen in a hydrocarbon. The example can be taken as cyclohexane ($\ce{C6H12}$) which is in a hydrogen-rich state. Its hydrogen-lean state is Benzene. I want to calculate the ...
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  • 1,633
6 votes
2 answers
91 views

Books and online resources to get me started in the finite element method (FEM)

In a course on the mechanical properties of materials, I have been asked to do a paper on the "Finite Element Method" to improve my current grade. However, most of the resources I find on ...
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2 votes
1 answer
139 views

Has it been researched whether face centered cubic carbon is stable?

According to this paper, carbon has a face centered cubic phase which is a metallic form. My question is: Has it been researched whether face centered cubic carbon is stable? Reasons why I'm ...
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  • 469
-4 votes
1 answer
114 views

Has there been research on improving the strength of graphene-based materials?

I read that brittle materials tend to have an observed strength much less than its theoretical strength because they tend to have surface cracks and whatever tension is applied gets greatly magnified ...
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  • 469
6 votes
0 answers
61 views

Value of density of state effective mass and transport effective mass to calculate conductivity [closed]

How can density of state effective mass and transport effective mass can be defined to calculate conductivity for a cubic system with parabolic but anisotropic dispersion relation? What will be the ...
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  • 1,515
7 votes
1 answer
138 views

How to study a new material without any experimental data about it?

My question is a little bit general. I want to study a 2D monolayer material which hasn't any experimental data available, just some first principles DFT works using PBE, LDA and HSE06 (for band ...
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  • 5,501
11 votes
1 answer
688 views

Selection of appropriate Langevin damping parameter for MD of solid metal

I am performing an MD simulation involving solid metal. The system is in the NVT ensemble, and I am using the Langevin thermostat (fix Langevin in LAMMPS) to enforce this. I have previously used the ...
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6 votes
0 answers
36 views

Is it possible to calculate the variation of magnetization M(T) for a diluted magnetic semiconductor? [closed]

Is there any simulation program (for example a DFT package) to determine the variation of magnetization M(T) for dilute magnetic semiconductors or doped semiconductors with different concentrations of ...
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5 votes
0 answers
42 views

What's the difference between dynamic and static strain aging? [closed]

I do understand how static strain aging occurs and why the yield point comes back if ample time is allotted after a loading and unloading cycles primarily due to diffusion of substitutional and ...
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5 votes
0 answers
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A doubt about extended dislocation [closed]

I wonder why this phenomenon occurs: "Unlike unextended screw dislocations, the extended screw dislocations define a specific slip plane, the {111} plane of the fault and it will be constrained ...
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14 votes
1 answer
128 views

What are the physical consequences of adding a constant to the diagonal of the effective Hamiltonian of monolayer materials?

Effective Hamiltonians modeling many-layered materials are often tuned using some sort of bias voltage. For instance, in a $4\times 4$ Hamiltonian matrix to describe biased bilayer graphene using some ...
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  • 2,091
6 votes
1 answer
70 views

Where is this extra plane coming from?

Why are there solid lines drawn connecting the solid circles after twinning has taken place? Ideally, that explains a real plane, isn't it? But why are we going to get a plane out of nothing if we ...
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5 votes
1 answer
109 views

Why does twinning take place in high rate of shock loading and low temperature?

To quote from a good textbook, which I don't remember: "Twins which are produced by mechanical deformation are called mechanical twins. Mechanical twins are produced in bcc or hcp metals under ...
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5 votes
1 answer
72 views

elastic constants transformation/basis change P21/a -> P21/n

I just calculated the stiffness tensor for a given material (a monoclinic molecular crystal) using molecular simulation. When trying to compare my results to published experimental results I found ...
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7 votes
1 answer
159 views

Can replacing some of the atoms in a covalent network with that of the element one atomic number higher make it nonstick? [closed]

I originally made the title the question I had that is a more suitable question but then it ended up too long. I had the idea that if you replace some of the atoms in a covalent network with the atom ...
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8 votes
1 answer
72 views

What are the possible applications of DIC (digital image correlation) in mechanical testing and the field of materials science?

I would like to know about possible applications of DIC in mechanical testing and the field of materials science, when I search there is the general topics of DIC usages, but I would like to know ...
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12 votes
1 answer
153 views

Has a form of diamond with certain properties ever been theorized?

The following is what a Penrose tiling looks like: I know the verticies of a dodecahedron can be grouped into 5 groups each of which are the verticies of a tetrahedron. So I thought of the idea that ...
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  • 469
9 votes
2 answers
303 views

Why are my publications getting accepted without much review from some journals, but getting rejected by the journal Computational Materials Science?

My field of research is computational materials science/mechanics. My work is on the "numerical modeling of shot peening process". This is a typical publication in my field. My work is not ...
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  • 101
11 votes
1 answer
183 views

Calculating hyperpolarizability in NWChem

I'm trying to make a pipeline geometry optimization -> calculation of polarizability/hyperpolarizability. And NWChem seems pretty good for it, the only thing I can't understand its how to calculate ...
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8 votes
1 answer
122 views

Are there other kinds of stability of materials? How to demonstrate that with computation approaches?

I have known some kinds of stability of materials, such as: Mechanical stability; Dynamical stability; Thermal stability In particular, they can be studied with first-principles computational ...
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  • 13.6k
11 votes
1 answer
134 views

How can we make a mechanically unstable cubic system, stable

I have to calculate the elastic constants of a Cubic system using a Density functional theory-based software. A cubic system will be mechanically stable if it satisfies the Born-stability condition (...
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  • 1,633
6 votes
1 answer
59 views

How to understand effect of increase in band gap generated away from Fermi energy on conductivity?

An example would be that when we dope Nitrogen in graphene its conductivity decreases. This can be explained through other means. But can this be explained through the change in its band structure?
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12 votes
1 answer
111 views

How can one computationally determine the flammability of a molecular system?

I can imagine one aspect of flammability (the ability of a substance to ignite on fire) to include calculating the kinetics and thermodynamics of the reaction of the system with oxygen. This is not ...
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