On 8/28/26 03:52, Simon Michnowicz via users wrote:
Dear User List
I am helping a researcher install Quantum Espresso. I find different
combinations of compilers/libraries produce slightly different results
upon a sample input given to me. The researcher said the results should
be consistent up to 5 decimal points. Is the variation that I see to
be expected, or could there some other problem here?
Tool Final Energy
Intel Compiler,MKL -314.1147158171
gcc/15.2.0-gcc-11.5.0/MKL -314.1256316418
gcc/11.4/openblas -314.1256341822
no, the difference between the first result and the two next is vastly
larger than expected. But: what kind of calculation is this? in some
cases (e.g., variable-cell calculations, DFT+U), small unavoidable
numerical discrepancies may build up and lead to more significant
differences in final results.
Paolo
much thanks
*---
Simon Michnowicz *
Senior Application Specialist, High-Performance Computing
*Monash eResearch Centre*
Monash University
15 Innovation Walk, Building 75, Clayton Campus
Wellington Road, VIC 3800
Australia
T: +61 3 9902 0794
M: +61 3 0418 302 046
E: [email protected] <mailto:[email protected]>
monash.edu <http://monash.edu/>
_______________________________________________________________________________
The Quantum ESPRESSO Foundation stands in solidarity with all civilians
worldwide who are victims of terrorism, military aggression, and indiscriminate
warfare.
--------------------------------------------------------------------------------
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
--
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 208, 33100 Udine Italy, +39-0432-558216
_______________________________________________________________________________
The Quantum ESPRESSO Foundation stands in solidarity with all civilians
worldwide who are victims of terrorism, military aggression, and indiscriminate
warfare.
--------------------------------------------------------------------------------
Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
users mailing list [email protected]
https://lists.quantum-espresso.org/mailman/listinfo/users
