Author Topic: about the MD analyzer---voidsize distribution  (Read 2370 times)

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Offline caocao

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about the MD analyzer---voidsize distribution
« on: May 3, 2017, 03:55 »
Dear there,

Could anyone explain the meaning of the parameters (resolution and element) and the plots in the MD analyzer/voidsize distribution.

Thanks very much

Offline Julian Schneider

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Re: about the MD analyzer---voidsize distribution
« Reply #1 on: May 3, 2017, 16:38 »
The voidsizes are a measure for how evenly the atoms in a material are distributed. This is primarily of interest for amorphous materials, as the atoms are arranged in an irregular manner.
What you measure is essentially the volume of the void space between the atoms.
This volume is calculated by first creating a Delauney traingulation (https://en.wikipedia.org/wiki/Delaunay_triangulation) of the atoms in the system, and then calculating the tetrahedral volume for each simplex. The size of a void is then calculated as the diameter (in Angstrom) of a sphere with equivalent volume.
The Voidsize Distribution analysis gives the distribution of these sizes in the system.
The Element selection lets you select only a subset of elements for whcih the voidsaize should be calculated, but the most common case would be that would calculate the voidsize for all elements in the system.
The Resolution selection lets you choose the bin size that is used when calculating the histogram of the void sizes.

Offline caocao

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Re: about the MD analyzer---voidsize distribution
« Reply #2 on: May 4, 2017, 03:56 »
Thank you very much for your reply.

As have been mentioned in your comments, if i calculate the voidsize distribution of amorphous MOx, and the element M is chosen.
does that mean the voidsize between M and M atoms will be calculated?

Actually, I want to know the change in the voidsize distribution around M atoms in amorphous MOx depending on the x value.

Thanks in advance!

Offline Julian Schneider

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Re: about the MD analyzer---voidsize distribution
« Reply #3 on: May 4, 2017, 11:20 »
If you select only M, then the voidsize calculation is performed only on the M atoms in the system, i.e. all other atoms are ignored.

Offline caocao

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Re: about the MD analyzer---voidsize distribution
« Reply #4 on: May 5, 2017, 07:35 »
Thank you very much for your kind help!

best wishes