RPA calculations and memory problems

[claudio]

Dear yambo developers

I'm tring to perform an RPA calculation for a large system, and I have a problem with the memory requirement,

Code: Select all

[M  7.757 Gb] Alloc X ( 7.739)

I'm using yambo 4.1.

In the old yambo version I solved this issue setting the variable

Code: Select all

EMStpsXd= 100.0000           # [Xd] [o/o] Memory Energy steps

to a small value in such a way to allocate only a fraction of the dielectric constant.
Now it seems that in the new yambo this variable is present, (yambo -o c -V resp)
but it does not work any more.

Any suggestion?

Ciao
Claudio

[Davide Sangalli]

Ciao Claudio,
I maybe wrong but I think the last yambo version with such feature was 3.3.1.
It was removed for some reason starting from version 3.4.0 (although the input variable is still there.)

Indeed the last version with the loop on "iw_group" in O_driver.F is 3.3.1, where the allocation of X_mat is "call X_alloc('X',(/X%ng,X%ng,wv%n(2)/))"
After that the allocation of X_mat became "call X_alloc('X',(/X%ng,X%ng,n_freqs/))"

An easy why to reproduce such behavior (for yambo -o c) could be to run yambo -o c "n times" each time with a "sub energy range" (and thus a fraction of frequencies) in input and then mount the result in output.

Hope it helps.

Best,
D.

[claudio]

Thanks Davide

here my script to solve this problem

http://www.attaccalite.com/rpa-calculat ... e-systems/

ciao
Claudio

[Davide Sangalli]

Ciao Claudio,
thanks you for the script.

You may like to have the script part of yambo-py:
https://github.com/henriquemiranda/yambopy

Henrique did a lot of work on that.
There are also tutorials available.

D.