Questions tagged [terminology]

Questions seeking clarification on the various terminology related to materials modeling.

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4
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0answers
49 views

Space group will not change in vesta

I have one unit cell of 16 atoms (4 formula unit cells) 2x2x2 unit cells. I want to construct the supercell with 32 and 64 atoms. I went in the transform and I changed the rotation matrix 4x2x2 and ...
9
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3answers
2k views

What does "force field" mean?

In MD simulations we often hear the term force field. What is it? We know, for example that, Gromacs provides various types of forcefields.
9
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1answer
329 views

Proposing a 2D quasicrystal; what are the necessary and sufficient conditions? (If it looks like a duck and quacks like a duck, or...?)

Quasicrystals show repeating motifs or patterns but are not periodic. And yet their Fourier transforms invariably demonstrate a pattern of sharp peaks revealing that there is still an underlying... ...
5
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1answer
42 views

What is the meaning of Coulomb Subtraction?

Specifically, in the General Utility Lattice Program (GULP) 2003 paper, in the methods section on Two-body Short-range Interactions we have the following: For covalently bonded atoms, it is often ...
5
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1answer
41 views

What does the "pn" column mean in this pseudopotential file?

In this SSSP pseudopotential file for Quantum ESPRESSO, what does the "pn" column mean?
6
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1answer
60 views

What is the polarization catastrophe?

I heard about the polarization catastrophe in a talk about polarizable force fields. The speaker talked about how the dipole induction is damped at short range to avoid the “polarization catastrophe&...
19
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2answers
447 views

What is a chemputer?

I first saw the term "chemputer" when reading about the work of Neil Ostlund (who you may know as one of the authors of the famous book "Modern Quantum Chemistry"). Based on the ...
6
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1answer
222 views

How is the material $\ce{\alpha-NaMnO2}$ pronounced?

I am a theoretical physicist, so I am not very familiar with chemical names. The material I am interested in is $\ce{\alpha-NaMnO2}$. Would that be pronounced alpha sodium manganese dioxide? Is it ...
11
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2answers
1k views

Is there any specific name for non-ferrous metals which are not noble metals?

In German there is the name "Buntmetalle" which means "colorful metals" for non-ferrous metals which are also not noble metals: Cadmium (Cd), Cobalt (Co), Copper (Cu), Nickel (Ni),...
24
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2answers
787 views

What is matter modeling?

Perhaps a stupid question, but.. what is matter modeling? I've never heard of it, and a google search just returns news articles about this site that seem to assume you already know what it is. I can'...
12
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1answer
162 views

What does a density of states (DOS) plot show?

I have plotted the density of states using GGA-PBE exchange correlation functional for magnesium silcide but I really do not know what the equations involved are in this process, and how they relate ...
6
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1answer
105 views

What is the meaning of energy-consistent and shape-consistent in the context of pseudopotentials?

I am trying to use pseudopotentials to model scattering from heavy molecules. However, I am confused by some of the terminologies of pseudopotentials/ECPs: Norm-conserving according to Wikipedia and ...
18
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4answers
1k views

How to explain Miller indices to someone outside nanomaterials?

I often find that when talking to experimentalists outside of the field of nanomaterials, it is nearly impossible to explain Miller indices concisely. As this often comes up during talks from other ...
12
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1answer
113 views

What does it mean to assign group operations to distinct sets for space groups?

I am trying to understand space groups in crystallography. In International tables for crystallography, for a nonsymmorphic space group, they list some symmetry operations. 8 of them are listed under ...
14
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2answers
2k views

High-Performance Computing: What does "Mio CPUh" mean?

Sorry if this question is too simple for the community but I really could not find an explanation. A detailed answer would be appreciated.
9
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1answer
137 views

What are the types of Quantum Molecular Dynamics (QMD)?

In similar spirit to recent questions on Quantum Monte Carlo, ab-initio Molecular Dynamics, types of SCF, and others, I would like to ask: What are the types of Quantum Molecular Dynamics (QMD)? As I ...
14
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1answer
794 views

What are "first principles" calculations?

A newcomer to density functional theory calculations is exposed to jargon which sounds rather non-technical at first. For instance, 'charge density' is something that is actually a term in the ...
26
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5answers
2k views

What are the types of DFT?

Similar to: What are the types of charge analysis?, What are the types of bond orders?, and What are some recent developments in density functional theory?, I would like to ask: What are the different ...
11
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1answer
293 views

What does capital sigma followed by an integer (Σn) mean in the context of grain boundaries?

I've just run across a nomenclature for coincidence lattices at grain boundaries which uses a capital greek letter sigma followed by an integer. For example Grain Boundary Engineering & ...
11
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1answer
198 views

How would you report the lattice parameters of an alloy, modelled using a supercell

There is a whole lot of literature behind ab initio modelling of alloys with statistical site occupancies. These include VCA, SQS, CPA, supercell approach, etc. This question does not aim to compare ...
13
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5answers
395 views

What are the common acronyms in Materials Modelling?

Many abbreviations are used in Materials Modelling. For example, we have DFT (density functional theory/discrete Fourier transform), TST (transition state theory) and MD (molecular dynamics). Which ...
18
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3answers
693 views

What are the types of ab initio Molecular Dynamics?

I am new to the world of Molecular Dynamics, and am curious to know exactly what is considered to be an ab initio Molecular Dynamics (AIMD) method, and how do they work? The seminal work by Roberto ...
9
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1answer
108 views

What are the types of DMRG?

The following questions have worked out very well 😊 : What are the types of Quantum Monte Carlo? What are the types of SCF? What are the types of MCSCF? What are the types of ab initio Molecular ...
9
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1answer
504 views

What is the meaning of fat bands?

I came across the band structure colored as bellow1: As you can see, each band was colored depending of the atom contribution to each band. Googling, I found it was done using the concept of fat ...