enabling PBC and Regularization at the same time increases error

[mumairsadiq]

Regularization and PBC work well when only one of them is selected.

Results are incorrect when both of the options are selected,

[mumairsadiq]

Regularization and PBC work well when only one of them is selected.

Results are incorrect when both of the options are selected,

Hi @jooooow , I have found the error I think,

Currently, I have tested some examples where the fix works well. I will test it further and then create a pull request.

[jooooow]

@mumairsadiq
Yes you're right.
As written in the README.md,

WARNING : currently, enable PBC and Regularization at the same will increase the error

When regularization is used, the cells are extended to contain some extra regularized bodies.
These regularized bodies are used to compute the multipole and local expansion, as well as the non-regularized bodies.
The existance of regularized bodies ensures the correctness of regularization, but also introduce large error when i>0.
When i>0, cells are copied and put arround the original box recursively.
Consequencely, some extra regularized bodies will also be added to the outermost edge, which result in a large error.

Recently, I'm working on fixing this problem(on branch 3-ewald-fmm) and found it's not an easy job.
But ofcause, i will apprecriate it if you can fix it.

[mumairsadiq]

Actually, I tried a tactic,

So far it is producing correct result when we run with combined regularization and PBC setting

Let me test it futher and see if the solution works correct for all scenarios.

[jooooow]

I invited you to a previous repo.
You can take a look at issue-1 for some reference.

[mumairsadiq]

Sure, thank you.