Author Topic: $rpacor $maxcor $ricore questions  (Read 1693 times)

inozerox

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$rpacor $maxcor $ricore questions
« on: June 11, 2016, 12:06:14 am »
Hello everyone.

I have some questions related to $rpacor $maxcor and $ricore.

Do all of them use a RAM memory? Hard disk?

Which combinations of them is the most convenient in order to perform the following calculations?

Optimizing the first singlet excited state, performing a TD-DFT calculation, Geometry Optimization using SCS-MP2 level (ricc2) and Geometry Optimization using a Hybrid Functional (DFT).

I apologize for asking a lot. But, I have been using Turbomole since 3 years ago and I just realize that maybe I have been making a mistakes respect to memory assignment.

Thanks in advance

All the best


christof.haettig

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Re: $rpacor $maxcor $ricore questions
« Reply #1 on: October 07, 2016, 01:59:12 pm »
All three of them refer exclusively the RAM.

$rpacor is special for the rirpa, $ricore for ridft, rdgrad, escf?, egrad?, rirpa?, aoforce? and might be replaced in the future by $maxcor

$maxcor is the orginal variable for the max. amount of RAM used by the TURBOMOLE programs for dynamic memory allocation in the Fortran code.
Note that on top of that the binaries need some memory themself and on Linux the MKL library, which is used for the linear algebra stuff, allocates
internally some extra RAM and the operating system needs some RAM to buffer I/O.
As a rule of thumb, we recommend to set $maxcor to about 66 - 75% of the physically available RAM, if you don't have a better estimate.

ricc2, ccsdf12, pnoccsd, mpgrad and mpshift use exclusively $maxcor. They ignore $rpacor and $ricore.

Christof

inozerox

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Re: $rpacor $maxcor $ricore questions
« Reply #2 on: March 22, 2017, 08:10:03 pm »
Thanks christof.haettig for answering me my question.

Thinking about the answer that you give me. I have another question.

If I try to set up two calculations at the same machine. Do I need to assign the 75% of RAM memory of that machine in both cases?

Thanks in advance

christof.haettig

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Re: $rpacor $maxcor $ricore questions
« Reply #3 on: March 23, 2017, 03:08:00 pm »
Of cause not.... You should assign to each job only 75% of the RAM that is availlable for that particular calculation.
If you run several calculation on one machine you need in advance decide how you want to split the total available RAM for the jobs.
If both have about the same size the best would be to give each of them half of the RAM --> set $maxcor to about 37.5% of the total RAM.

inozerox

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Re: $rpacor $maxcor $ricore questions
« Reply #4 on: May 09, 2017, 09:50:49 pm »
Thanks for all christof.haettig.

 :D