Dear all,
I'm trying to perform a QM/MM calculation which makes use of DLPNO-CCSD(T)-F12/D for the high level, and XBT for the low level. My input looks like this for ORCA:
!QM/XTB DLPNO-CCSD(T)-F12/D cc-pvtz-F12 cc-pvtz-F12-CABS cc-pvtz-F12-MP2fit DefGrid2 SmallPrint Opt NUMGRAD
%qmmm
QMAtoms {0:12} end
end
* xyz 0 1
coordinates for moleclues
*
I have been trying to get ORCA to run this calculation, but it keeps crashing after 3 hrs with the following error:
--------------------------------- --------------------
FINAL SINGLE POINT ENERGY (L-QM2) 0.000000000000 (Wavefunction not fully converged!)
--------------------------------- --------------------
[file orca_main/main_util_tools.cpp, line 549]: Cannot open gbw file
[file orca_main/main_util_tools.cpp, line 549]: Cannot open gbw file
However, the gbw file is there. So I was wondering what I could do to remove this error?
try adding accelerators for SCF:
! KDIIS SOSCF LSHIFT
well and maybe increase the number of steps in SCF
Thanks Andrey! Is there a way to increase the number of iterations for xBT? I see the default is 250, and wondered if increasing this value would help as well.
Yes.
number of iterations for XTB is given by:
%xtb
XTBINPUTSTRING "--iterations 2000"
end
Thanks again Andrey for the suggestion. I have tried using %xbt in my scripts, but ORCA 6 doesn't seem to recognise it. I have been attempting to implement it as shown below. Would this be the correct way of doing it?
%xtb
maxiter 500
end
No, it won't work that way.The number of iterations can only be increased by passing arguments directly to otool_xtb, and this can only be done via XTBINPUTSTRING (see manual 6.0.1, p. 491)
- Badges
- Science topic
- Similar topics
- Thesis Research