Author Topic: Boundary conditions -reg  (Read 2313 times)

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Offline GJK

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Boundary conditions -reg
« on: February 27, 2014, 03:19 »
Hi,

In ATK 12.8 we are having three options in the Poisson Solver
1.Multigrid
2.FF2D
3.FFT

What solver should be selected for
1.Molecular Optimization
2.Device Optimization
3.Bulk optimization

Thanks in Advance

Offline Umberto Martinez

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Re: Boundary conditions -reg
« Reply #1 on: February 27, 2014, 11:22 »
device: use FFT2D unless you have spatial regions, then Multigrid.
bulk: FFT unless it is charged. In that case you will need Multigrid
molecule: Multigrid, multipole

then there are some special cases that you may consider, see for example the slab calculations in this tutorial: Tuning the work function of silver by deposition of ultrathin oxide layers

Offline GJK

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Re: Boundary conditions -reg
« Reply #2 on: March 2, 2014, 17:01 »
Kindly explain me about spatial regions in a device and about multipole

Offline GJK

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Re: Boundary conditions -reg
« Reply #3 on: March 3, 2014, 18:32 »
Hi,

Kindly provide me an explanation of your following reply-
device: use FFT2D unless you have spatial regions,
bulk: FFT unless it is charged
molecule: Multigrid, multipole

Give some references or suggestions

Thanks in advance