# Tag Info

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### What are the common acronyms in Materials Modelling?

I will start with acronyms for coupled-cluster, and someone else might answer with acronyms for basis sets or for functionals or for many body perturbation theory or for composite approaches or for ...
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### What is Materials Modeling?

I'm just as curious of a user here as you, but I was able to find that a Materials Modeling Wikipedia page does in fact exist. :) Computational materials science and engineering uses modeling, ...
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### What is matter modeling?

"Matter modeling" is a term that was coined by Stack Exchangers! That's why the words "matter" and "modeling" next to each other, don't seem to exist in any of the ...
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### How to explain Miller indices to someone outside nanomaterials?

You can see it with VESTA software. For example, we can see the different lattice planes of NaCl crystal. [001] plane of NaCl: [101] plane of NaCl: [111] plane of NaCl:
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### What are the types of DFT?

CDFT: Current DFT Current DFT is defined via the generalized Hohenberg-Kohn theorem (HKT), which extends the traditional HKT to account for the effect of magnetic fields. The generalized HKT says that ...
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### What is Materials Modeling?

Answering your last questions: yes, yes and yes. One thing to consider is which approach do you want/need to use. You can use an atomistic approach where you simulate/model the properties and the ...
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### What are the types of DFT?

OF-DFT: Orbital-free density functional theory Hohenberg and Kohn established that the ground state energy, $E$, of interacting electrons in a potential, $v(\mathbf{r})$, is a functional of the ...
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### High-Performance Computing: What does "Mio CPUh" mean?

"Mio" refers to "Million" and "CPUh" is the abbreviation of CPU hours, also refered to as Core hours. This is a good read if you need to know more about HPC. This is an ...
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### What does "force field" mean?

What is a force field? The Wikipedia entry on this is a good resource, but I'll give my own description below. In the context of molecular dynamics (MD), a force field is one way of describing the ...
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### What are "first principles" calculations?

First Principles mean starting directly at the level of established science and not making assumptions such as any empirical models or parameter fitting. With respect to DFT, EMF (Electromagnetic ...

### How to explain Miller indices to someone outside nanomaterials?

Assuming a generic chemistry background I wouldn't assume that knowledge of crystal structure would be too in depth at an undergraduate level. It is definitely encountered, but depending on the type ...
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### What are the types of ab initio Molecular Dynamics?

CPMD: Car-Parrinello Molecular Dynamics An approximation of BOMD (Born-Oppenheimer MD) where fictitious dynamics is used on the electrons to keep them close to their ground state, so that we do not ...
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### Is there any specific name for non-ferrous metals which are not noble metals?

I don't think it's ideal, but there is the term "base metal". There are various definitions for what is considered a base metal, but the main noble (or precious) metals are always excluded. ...
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### How is the material $\ce{\alpha-NaMnO2}$ pronounced?

The anions of the form $\ce{MnO_x^y-}$ are referred to as manganates (see Wikipedia). I'm not sure if there might be a "special" name for $\ce{MnO2^-}$ specifically (that's the species you have here) ...
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### What are the common acronyms in Materials Modelling?

Density Functionals LDA (LSDA): S: Slater (Dirac) exchange functional for a uniform electron gas. VWN: Vosko, Wilk, and Nusair 1980 correlation functional fitting the random phase approximation ...
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### What is matter modeling?

First of all, we assume the matter is constituted by nuclei and electrons, as illustrated by the following figure: Mathematically, the matter is mapped into the following Hamiltonian: H=T_e + T_n + ...
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### What are the common acronyms in Materials Modelling?

Basis Sets Throughout, I use square brackets to denote additional options that can be included, but are not required. Slater: STO-nG: Slater Type Orbitals represented by a function of n contracted ...
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### What does capital sigma followed by an integer (Σn) mean in the context of grain boundaries?

The $\Sigma$ values represent the volume of the Coincident Site Lattice (CSL) of the grain boundary in terms of the volume of the unit cell of the crystal. In general, grain boundaries with higher ...
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### How would you report the lattice parameters of an alloy, modelled using a supercell

By making a supercell and modifying it in some way, you are creating an entirely new structure which you hope can give you some insight by being compared to the original structure. Any of the ...
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### What is a chemputer?

I am curious to know if the word has been used in any way other than the above three ways. Mark. J. Winter at University of Sheffield has used the word differently — not as a term meaning something ...
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### Different types of transition dipole moment in ORCA output

You have stumbled across a problem that was described in 1983 in the following way (note that the "40 years" refers to 1943-1983): "Over the past 40 years, many authors have tried to ...
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### What is a chemputer?

The term chemputer also refers to a universal chemical synthesis robot - this is because the robot uses a high level abstraction of chemical synthesis. From this approach we developed a programming ...
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### What does "force field" mean?

The term's origin goes back to vector field which is a function that returns a vector for any given point in space (as in the image below on the left). We can almost "see" that such fields ...
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### What are the types of ab initio Molecular Dynamics?

2nd Generation CPMD Car-Parrinello MD avoids repeatedly solving the electronic problem by propagating the orbitals as if they were particles governed by Newton's equations. This is much more efficient ...
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### What are the types of DFT?

KS-DFT: Kohn-Sham DFT The KS-DFT is proposed to deal with the problems of orbital-free DFT (OFDFT), which has been explained by @wcw. OFDFT attempts to compute the energy of interacting electrons, as ...
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### What are the types of DFT?

Density functional perturbation theory (DFPT) This method refers to the calculation of the linear response of the system under some external perturbation. Consider some set of parameters \$\{\lambda_i\}...
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### What does it mean to assign group operations to distinct sets for space groups?

When your lattice is primitive you have only the (0,0,0)+ set; when your lattice has some kind of centering (body- or face-centering) other sets are present, such as (1/2, 1/2, 1/2)+ or (1/2, 1/2, 0)+ ...
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### What does "force field" mean?

Molecular dynamics is based in Molecular Mechanics. Molecular Mechanics do many approximations in order to treat the atomic/molecular system. A good definition can be seen here: Molecular Mechanics ...
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