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Mon, 22 Jul 2019 13:40:36 +0200en-gbDFT geometry optimizations - by: bakowies
https://mrcc.hu/index.php/forum/running-mrcc/169-dft-geometry-optimizations#724
https://mrcc.hu/index.php/forum/running-mrcc/169-dft-geometry-optimizations#724
I have run into problems with DFT geometry
optimizations with MRCC and, when analyzing
results for FNO, noted that the "max force"
printed for convergence tests does not correspond
to the max value of all cartesian gradient
components printed just before.

Now this may be the case if the "max force"
is evaluated from some internal gradient. Trying
to confirm I did a little debugging with a self-compiled
code and then found that the "max force" was
taken to be the largest component of some
4-component vector. I cannot confirm what
this vector really is (I did not dig in any
deeper and lack knowledge of the code), but

a) FNO is bent, so an internal gradient
should have 3, not 4 components.
b) The "max force" printed at the last step
of the optimization is much smaller (2.6*10^-6)
than the largest cartesian gradient (10^-4),
see the output attached.
Even if the "max force" is from some internal
gradient, I would expect closer correspondence
with the maximum cartesian gradient component.
c) Side note: The printed "rms force" appears to
correspond to the norm, not the RMS value of the
4-component vector.

Other than for this debugging I only used the
precompiled 2019 binary downloaded from the MRCC
website. The attached output was generated with
the precompiled binary.

Any ideas?

Thanks a lot,
best regards,
Dirk Bakowies]]>Running MRCCMon, 15 Jul 2019 11:08:41 +0200Strange scf convergence between CCSDT and CCSD(T) scf for Iron - by: bkwx97
https://mrcc.hu/index.php/forum/running-mrcc/168-strange-scf-convergence-between-ccsdt-and-ccsd-t-scf-for-iron#719
https://mrcc.hu/index.php/forum/running-mrcc/168-strange-scf-convergence-between-ccsdt-and-ccsd-t-scf-for-iron#719
I am running a CCSD(T)/PVQZ and CCSDT/PVQZ computation on Fe. I'm experiencing something very odd wrt scf convergence. The CCSD(T)/PVQZ scf does not converge while the scf portion of CCSDT/PVQZ does. Does the hand coded CCSD code call a different scf solver? I'm attaching the inputs of the two. This has been ran on a binary of the Feb 2019 version.