7 votes

Exploring Elastic Constants Calculation in VASP: Methods and Best Practices

Theoretical Background: Elastic constants can be calcualted in one of two approaches. First is via the stress-strain relationship, and the second is by strain-energy relationship. First approach: In ...
Jaafar Mehrez's user avatar
4 votes

Elastic properties of graphene by using DFT (Quantum espresso)

The elastic stiffness $C_{j}$ with respect to each $j$ direction mediates the energy $E$ at a deformed structure and the mechanical strain $\epsilon_{j}$ as follows [Mir, S. H. et al. ACS Omega. 2020, ...
Patche's user avatar
  • 400
4 votes

How can I calculate the elastic properties of a unit cell and a supercell?

There is new tool called ElasTool. It is a Python-based toolkit for computing the second-order elastic constants (SOECs) and mechanical properties of crystal systems. It is designed to integrate with ...
Thomas's user avatar
  • 9,072
4 votes

Fitting of Brich-Murnaghan equation of state

If you know Julia, I have a package called EquationsOfStateOfSolids.jl that is designed to do this. It currently can fit and evaluate $E(V)$, $P(V)$, and $B(V)$ on several equations of state: ...
Ryan's user avatar
  • 176
3 votes

Fitting of Brich-Murnaghan equation of state

Here are some references from my own work: a script that reads energy-volume data from a csv file and fits a Vinet equation of state: https://github.com/flokno/tools.mlff/blob/main/mlfftools/scripts/...
flokno's user avatar
  • 136
2 votes

Assessing Accuracy of Elastic Constants for 2D Materials Calculated via VASP and VASPKIT

Symmetries The elastic constants tensor obtained should reflect the symmetries of the crystal structure of the material in question. This comment article can be a helpful reference. Elastic constants ...
CW Tan's user avatar
  • 1,266
2 votes

How can I calculate the in-plane stiffness and Poisson’s ratio of a graphene monolayer?

If you already have the elastic constants $C_{ij}$ (in Voigt notation), you should be able to use the following equations for the general angle-dependent in-plane Young's modulus $E(\theta)$ and ...
CW Tan's user avatar
  • 1,266
2 votes

How to calculate 2D elastic constants of boron nitride monolayers from uniaxial strains?

I think you should take a rectangular unit cell instead of the hexagonal unit cell depending on this article (The response of mechanical and electronic properties of graphene to the elastic strain M. ...
2 votes

How to compute the Elastic Modulus of a molecule using GROMACS?

You can apply certain strains to the system by modifying the input structure, e.g. stretching one direction and fixing the other directions. After running MD, one can extract stress components. Keep ...
Lukas's user avatar
  • 151
1 vote

Supercell Elastic Constant

In the undoped case, when considering a cubic crystal structure and using a tetragonal supercell not changes point symmetry, Hence number of independent elastic constants remains three. If you rotate ...
Pranav kumar's user avatar
  • 4,108

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