ONIOM in CP2K

[daniel Storm]

Hi everyone,

To provide some context, I am working with an iridium organometallic salt, [Ir(PONOP)(H)Me][BAr^F₄] and my goal here is to do a QM/MM type calculation where my MM region is treated with xTB.

I have tried my best to piece together an ONIOM input file from what I’ve seen on the internet but it’s not quite right. I keep getting a CPASSERT error suggesting that there is an issue with how the fragments are numbered? I’ve double-checked those and it looks correct to me.

My QM region (Fragment 1) are atoms 406-545

My xTB region (Fragment 2) are atoms 1-405

Any help with this issue or information on how to correctly construct an ONIOM input file would be much appreciated. I have attached my attempt and output files below.

Thanks,

Daniel

[Marcella Iannuzzi]

Hi 

I think you need to specify 

MULTIPLE_SUBSYS T

in &MULTIPLE_FORCE_EVALS .. &END

 Kind regards

Marcella

[daniel Storm]

Hi Marcella,

Thanks for your response.

I tried including MULTIPLE_SUBSYS T in the MULTIPLE_FORCE_EVALS section and unfortunately that gives me the same error as before.

I have also tried varying the size of my QM region. This system has 4 cations and 4 cations in it with an overall charge of 0. I’ve tried having my QM region as;

-              -   1 cation (Charge 1)

-              -   1 cation + 1 anion (Charge 0)

These unfortunately produce similar errors to above.

Kind regards,
Daniel

[Marcella Iannuzzi]

Shouldn't you pass to each FORCE_EVAL its own coordinates file?

See the test cp2k/tests/FE/regtest-1/Solv_alch_chng_simpl.inp

In your input it seems that each FORCE_EVAL gets the same coordinate file

Kind regards

Marcella