Hi,

Hmmm...even though the SI file of the paper you have shared does point to using HSE06, it remains not entirely clear whether its parameters were kept default or altered (for all systems together or individually for instance).

There are also differences between what different codes consider as "default" settings. For example, within the code used in the paper (VASP, nice code, no doubt), the defaults for HSE06 read (taken from https://www.vasp.at/wiki/index.php/List_of_hybrid_functionals) :
$$ \omega= 0.2\ \mathring{A} , \quad c = 0.25, \quad \text{correlation}=\text{PBE}, $$ with the first number reading the range separation parameter (omega) and the second the fraction of exact exchange used (c).

Within CRYSTAL (also nice code, no doubt), these read (taken from the manual, page 138):
$$ \omega= 0.11\ a_0^{-1}, \quad c = 0.25, \quad \text{correlation}=\text{PBE}, $$ adopting the same labels.

Not sure about the exact definition of units (perhaps a developer can comment if this is indeed Bohr radius as assumed?), but you can already see the subtle differences having to be taken into account when comparing between codes.

A few other thoughts worth considering:

• In the paper, the structure was optimized with PBEsol and on top of that geometry HSE06 was applied as a single-point calculation. Not sure about the exact composition of those ZIFs, but the structural differences could play a significant role as well (planewave codes are very costly when optimizing a structure with hybrid functionals). Here is also a good read on this topic: doi.org/10.1088/2516-1075/aafc4b

• One final small comment. Within the PAW formalism implemented in VASP, scalar relativistic effects are included in the pseudopotentials by default. No problem, cool feature, but should be taken into account when comparing results, especially for heavier elements (longer discussion found here https://blog.vasp.at/forum/viewtopic.php?t=902)

Hope this helps!

Cheers,
Aleks

Hi,

from a quick look at your input/output files, it doesn't seem that the intel error is the final one, as the code started struggling with converging the SCF solution. You can monitor the behaviour with each cycle, where at cycle 8 you end up with:

...
 TTTTTTTTTTTTTTTTTTTTTTTTTTTTTT NUMDFT      TELAPSE      156.79 TCPU      151.49
 CYC   8 ETOT(AU)                 NaN DETOT       NaN tst  7.97E+01 PX  1.03E+02
 TTTTTTTTTTTTTTTTTTTTTTTTTTTTTT MPP_TRAF    TELAPSE      157.35 TCPU      152.05
...

after which the code stops. Without unnecessarily repetition, I would rather point you to a great source itself:
https://tutorials.crystalsolutions.eu/tutorial.html?td=SCF_conv&tf=conv_tut

Give a shout if you still struggle after trying those things.
And perhaps this part could be moved to the geometry optimization sub-topic.

Cheers,
A

Dear Gryffindor,

I had a quick look at your input/output files. You have increased the number of cycles for which the number of (up-down) electrons will be fixed, without increased the actual number of SCF cycles. This can be done with the MAXCYCLE keyword. For example, in your input file:

...
SHRINK
1 1
MAXCYCLE
200
SPINLOCK
0 100
...

You can always verify that by checking the exact value in the output file, which in your case reads:

...
*******************************************************************************
 MAX NUMBER OF SCF CYCLES      50  CONVERGENCE ON DELTAP        10**-16               <---
 WEIGHT OF F(I) IN F(I+1)      30% CONVERGENCE ON ENERGY        10**- 6
 SHRINK. FACT.(MONKH.)    1  1  1  NUMBER OF K POINTS IN THE IBZ      1
 SHRINKING FACTOR(GILAT NET)    1  NUMBER OF K POINTS(GILAT NET)      1
 *******************************************************************************
...

Also, a final note, care is advised to not have the number of SPINLOCK cycles for too long as you might converge while locking is active. Ideally, the SPINLOCK directive should remain active until the SCF process has found a numerically stable path along for which the system converges to the required configuration.

Hope this helps,
Cheers,
Aleks

Hi,
if you could add your input/output files or something like screenshots of the same, that could be a good start for debugging!
Cheers,
A