POV-Ray : Newsgroups : povray.binaries.images : Granite_21 - the final macro : Re: Granite_21 - the final macro Server Time
26 Sep 2022 03:18:45 EDT (-0400)
  Re: Granite_21 - the final macro  
From: Samuel B 
Date: 21 Sep 2021 19:40:00
Message: <web.614a6c5fb21f010ccb705ca46e741498@news.povray.org>
"Bald Eagle" <cre### [at] netscapenet> wrote:
> "Samuel B." <stb### [at] hotmailcom> wrote:
> > > > All my attempts have failed. There is probably a basic solution
> > > > and I'm just over-complicating things...
>
> Doesn't seem that way.  Having never done any of this type of work, in my
> ignorance, I believe I was initially suggesting an overly simplistic approach.
>
> OK, here's the deal.
>
> from: https://en.wikipedia.org/wiki/Miller_index
> .... a family of lattice planes is determined by three integers h, k, and
> ℓ, the Miller indices. They are written (hkℓ), and denote the family
> of planes orthogonal to hb1 + kb2 +lb3, where bi are the basis of the reciprocal
> lattice vectors....
>
> from which I can see that the key part is incorporated by reference at
> https://en.wikipedia.org/wiki/Reciprocal_lattice
>
> The reciprocal lattice is the set of all vectors Gm, that are wavevectors of
> plane waves in the Fourier series of a spatial function which periodicity is the
> same as that of a direct lattice Rn

Thank for the time you took to research this! It's indeed probable that the
reciprocal lattice is the way forward. I'll read through the articles and try to
glean some useful info from them.

Unfortunately, I've got two things holding me back: my inability to parse
mathematical formulas due to only being self-taught; and my inconsistent mental
energy. Most people suffer from the latter, but it seems I am particularly
affected by such fluctuations :S

> So:
>
> The guy you want to talk to is Michael Joseph Waters - a postdoctoral researcher
> in X-ray crystallography at Northwestern.  Nice guy - we emailed back and forth
> a while back.
> "NiO is a odd material, it's antiferromagnetic so there are alternating planes
> of spin up and spin down electrons. If you learn Miller indices, these are on
> (111) planes."

I'm intrigued by that. What sorts of special properties does Nickle(II) oxide
possess, I wonder?

> Also:
> https://ciderware.blogspot.com/2016/08/getting-isosurfaces-from-data-grid-into.html
>
> Find his contact info here:
> https://mtd.mccormick.northwestern.edu/group/
>
> He's likely a busy guy, but he may have some advice on how to approach
> unraveling this all.  I'm guessing it might take a 3rd party software package -
> or maybe not, if we can use the FFT that I coded up a while back.

FFT=fast Fourier transform? What have you been using it for? (Sorry for being
out of the loop, haha.)

And I'd hate to bother him to pick his brain, but I do know some people like to
talk. Heck, maybe the creator of KrystalShaper would be willing to share the
code he used to convert HKL indices to planes.

Thanks again, and I will be looking into the matter further. I'm betting the
conversions for various crystal symmetries are actually super easy to
implement...

Sam


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