# Questions tagged [mathematical-modeling]

Questions related to mathematical modeling of materials systems.

15 questions with no upvoted or accepted answers
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### Is there a software that can do derivatives with respect to user defined vibrational modes?

I'm doing some property calculations that depend on a sum of derivatives of some quantity with respect to normal vibrational modes. I was hoping to find some physical intuition relating the type of ...
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### A viscoelastic material with nonconvex memory kernel?

The title is basically my question. Viscoelastic materials are characterized by a constitutive equation between stress and strain involving a convolution integral. This integral is weighted with a ...
• 131
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### Database (or table) of functions obeying symmetry properties of space groups

I'm looking for a table or database containing mathematical functions that belong to crystallographic space groups by having the same symmetry elements. Imagine a 2D square planar lattice. It has a 4-...
• 141
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### How can I properly plot this .cube file in Python?

Motivation for Post: I saw a question about how to plot a .cube file recently on the Mathematica & Wolfram Language Stack Exchange. It was marked "off-...
• 133
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### How can one determine the time-step for imaginary time evolution?

The real-time evolution of a quantum system described by the state $\psi(t)$ is formally given by, $$\psi(t+\Delta t) = \exp^{- i \hat{H} \Delta t / \hbar} \psi(t)\tag{1}$$ For dynamical simulations ...
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### Gauge constraint in the definition of the Z2 invariant

Cross-posted at Physics.SE. In Fu and Kane's paper from 2006, the authors define the $\mathbb{Z}_2$ invariant for time-reversal invariant topological insulators as an obstruction to Stoke's theorem, ...
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### Why are some point groups for single atoms listed as Oh in the CCCBDB?

Does anyone know why the CCCBDB database lists the tin cation and antimony atom as having the Oh point group (please see the screenshot below from CCCBDB when I look at "All molecules sorted by ...
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### Help with Mathematica for optimizing a Gaussian basis set for a hydrogen atom in a magnetic field

This is a follow-up to my previous question: Optimal Gaussian basis set for hydrogen atom in magnetic field Brief description of the problem I would like to find the ground and excited states of the ...
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### Convex hull calculations with WIEN2k

How does one do the calculation of a convex hull with the WIEN2k code for the formation energy of alloys?
48 views

### A problem to simulate the kinetic energy operator using some field going through a crystal

We know about a differentiation and integration operations and also other ones can be simulated by an analog way using electric circuits with operational amplifiers (here are articles of the ...
• 1,007
1 vote
30 views

### Difference between Phase Diagram and Convex Hull

in literature I sometimes see a mixed use of the words Phase Diagram and Convex Hull. However from my current knowledge, there are some differences between them. A phase diagram views the difference ...
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1 vote