size limit to Hessian calculations?

[natedey]

hi all,
Is there a perl-enforced size limit to the Hessian calculations? When I run a model that has 338 or greater atoms with calcfc, I get:

failed to open hessian at /home/qcheng1/git/xtb-gaussian/xtb-gaussian line 80.

Stack trace terminated abnormally.

------- xtb command was ---------
?> xtb ./Gau-114034.EIn -P 4 --gbsa h2o --input 1.fix --verbose --hess --charge -1 >/dev/null 2>Gau-114034.EMs >> xtbout

ExternalExternalExternalExternalExternalExternalExternalExternalExternalExternal

Recovered energy= 0.00000000000 dipole= 0.000000000000 0.000000000000 0.000000000000
FIO-F-217/formatted read/unit=31/attempt to read past end of file.
File name = /home/scratch/geward/2746189/Gau-114034.EOu formatted, sequential access record = 1017
In source file runexo.f, at line number 36

[tsuhagia]

If it ran using (--log-all) it will not limit as per my obeservation.

passing --log-all as the first argument to xtb-gaussian will mix in the (often very long) xtb output with the Gaussian output, which is not done by default for performance and easier parsing of Gaussian log files.

?> xtb ./Gau-114034.EIn --log-all --gbsa h2o --input 1.fix --verbose --hess --charge -1 >/dev/null 2>Gau-114034.EMs >> xtbout

[ncasetti7]

I was running into a very similar issue and what ended up fixing it was changing the version of xtb I was using. I was running into this error with xtb-6.5.0 and xtb-6.5.1 but have had success with xtb-6.4.1.

[natedey]

Thanks @ncasetti7
Is there anyone here familiar enough with the xtb source to identify what changed? It's not necessarily an xtb "bug" but maybe some accidental limit that has been imposed on the Hessian matrix size? Or an incompatibility with how Gaussian reads or writes the Hessian?