lda unitialized about mvmc HOT 5 CLOSED

I cannot ensure uncommenting lda = 2*n would make it work, but leading dimension for that matrix is indeed 2.

from mvmc.

Dear RuQing,

thank you very much for clarifying this. Could you please tell, what are the all changes required to be done in calculateNewPfMN_child and perhaps in M_ZSKPFA to make everything work?

Could you please share the version of the src/mVMC/locgrn.c file used in obtaining the results of https://arxiv.org/pdf/2005.14142.pdf ?

Thanks a lot!

Best wishes,
Nikita

from mvmc.

Dear Nikita,

Because I and RuXing are not authors of the arXiv paper,
we do not know the details of the codes used in the arXiv paper.
If you want to use the code, please contact the authors of the arXiv paper.

By the way, on the GreenFuncN, it is used in the power Lanczos calculations.
For example, in lslocgrn.c, we calculate the 3-body and 4-body Green functions
using GreenFuncN.
Could you refer to the usages of GreenFuncN?

Best,
Takahiro Misawa

from mvmc.

Dear Takahiro,

thanks a lot, this is a very good comment.

However, it is unclear to me how the function GreenFuncN can work properly in its current implementation.

As RuXing and me found out above, GreenFuncN calls calculateNewPfMN_child, where currently the parameter lda is uninitialized, and most likely during equals lda = 0 during execution (though this is not guaranteed).

Then pointer to lda is passed to M_ZSKPFA as 5th argument &lda, and I get an error from PFAPACK that 5th argument is invalid (note that LDA >= max(1, N)).

So, as I understand, in the lslocgrn.c file, where you calculate 3-body and 4-body GF, the execution of GreenFuncN never goes further line 254 (reduction stage, if some of the operators have matching indices).

I still believe that calculateNewPfMN_child in its currently commited way has an unexpected behavior.

Thanks for the advice, I will contact the authors of the very paper.

Best wishes,
Nikita

from mvmc.

Dear all,

I have correctly modified calculateNewPfMN_child and checked the result by explicitly looking at the Pfaffians ratios. Now I have the working 4-point function. I thank you a lot for your assistance.

Closing this.

Best,
Nikita

from mvmc.