ORCA Parallel Setup on Windows 11 Pro

In this tutorial the process of setting up ORCA in a parallel environment explained on Windows 11. An example input is also provided and successfully run.
ORCA installation on Windows 11 Pro: • ORCA Installation on W...
MS-MPI: learn.microsof...

[@DavidRandall-d5o]

Thank you. This was super helpful. In the the installer of ORCA 6.0.1, one has to click on "custom install" to install the parallel components also. That with the MS-MPI installs made the PAL4 key word work for me (and the calculation runs faster). Again, thanks, Professor Adam, for the clarity on installing the MS-MPI files from Microsoft.

[@profadam]

Thanks for the feedback! Glad it helped. I made this from my own frustration and confusion, I thought others might have the same problems.

[@oxfordtiger]

Something I didn't realize, and that isn't mentioned in most places I looked - the default installation of Orca does not include the files for parallel calculations. You have to install through the custom installation. It took me ages to figure this out!

[@profadam]

Ah yes, you're right, the default installation only contains the single core functionality.

[@ans128]

this solved my problems, thank you

[@profadam]

Happy to help.

[@jefflucas_life]

4:32 but... that's on just a single PC. Can orca be run across nodes, like how bitcoins are mined? There isn't much I can find to configure the MyMol.nodes in the working orca directory to be included with the INPUT file. I am looking how to run orca input file across multiple nodes not on a single desktop.

[@profadam]

Yes, this is for a single PC. I do believe it is possible to get it to work on multiple nodes but I haven't done it. I'd recommend checking out the official forums.

[@divyathomas4294]

Sir every time i try parallel computing, my command line aborts the mission, stating that the file orca_startup_mpiexec is not found. I have tried reinstalling all the orca files twice already. and have downloaded Microsoft MPI, but this error continues. Can Someone please help. Thank you.

[@profadam]

Were you able to successfully run it in serial mode?

[@felipesantis5046]

It works beautifully! Thank you so much!

[@profadam]

Glad it helped!

[@abhisheksharma2060]

@@profadam does parallel computing help to speed up calculations, because normally using 1 processor, water molecule was optimized within 20 sec but running on PAL8 it took 2 min? (spec-i5 9gen 32 gb ram)

[@고구-h8x]

it works! you are the best.

[@profadam]

Glad to hear that

[@albert4895]

Thanks. Very informative

[@NennetteDolatre]

very helpful thank you!

[@profadam]

Glad it was helpful!