[QE-users] hp.x Error in routine cdiaghg (270): problems computing cholesky

Thu Jan 25 12:59:45 CET 2024

Dear Iurii,

thank you for your response, yes I have noticed this, I thought HP can start from this 'false state' and calculate the U parameters to correctly reflect the Mott-insulator behavior. 
I also computed a few scf DFT+U with U value of V-3d ranging from 2.7 - 2.9 eV, many of which turned out to be metallic. See (LVO_U(La-4f)_U(V-3d_V(O-2p V-3d))): 

LVO_5.0_2.7_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.3585   13.4614: 1.1029
LVO_5.0_2.7_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.7936   12.7687: -0.0249
LVO_5.0_2.7_0.3/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.8425   12.8166: -0.0259
LVO_5.0_2.8_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.4686   13.3603: 0.8917
LVO_5.0_2.9_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.7631   12.7638: 0.0007
LVO_5.0_2.9_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.3092   13.5493: 1.2401
LVO_5.0_2.9_0.3/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.4914   13.4507: 0.9593
LVO_6.0_2.7_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.8108   12.8112: 0.0004
LVO_6.0_2.7_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.8090   12.7859: -0.0231
LVO_6.0_2.8_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.4816   13.3813: 0.8997
LVO_6.0_2.8_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.0800   12.6079: -0.4721
LVO_6.0_2.8_0.3/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.5317   13.4616: 0.9299
LVO_6.0_2.9_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.0412   12.5850: -0.4562
LVO_6.0_2.9_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.3227   13.5668: 1.2441
LVO_6.0_2.9_0.3/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.4946   13.4855: 0.9909
LVO_7.0_2.7_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.0819   12.6240: -0.4579
LVO_7.0_2.7_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.1313   12.6651: -0.4662
LVO_7.0_2.7_0.3/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.8713   12.8486: -0.0227
LVO_7.0_2.8_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.0475   12.5857: -0.4618
LVO_7.0_2.8_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.0963   12.6256: -0.4707
LVO_7.0_2.8_0.3/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.2079   12.7589: -0.449
LVO_7.0_2.9_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.0322   12.5719: -0.4603
LVO_7.0_2.9_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.0812   12.6120: -0.4692
LVO_7.0_2.9_0.3/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.1948   12.7461: -0.4487
LVO_8.0_2.7_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.1005   12.6553: -0.4452
LVO_8.0_2.7_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.1584   12.6600: -0.4984
LVO_8.0_2.8_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    13.1190   12.6864: -0.4326
LVO_8.0_2.8_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.8723   12.8683: -0.004
LVO_8.0_2.9_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.8057   12.8032: -0.0025
LVO_8.0_2.9_0.15/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.8566   12.8521: -0.0045
LVO_8.0_2.9_0.3/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.9079   12.9012: -0.0067

Would you suggest to take a parameter set from this (e.g LVO_5.0_2.7_0.0/scf2.out:      highest occupied, lowest unoccupied level (ev):    12.3585   13.4614: 1.1029) and start the HP scheme from there on?

All the best,
Simon

Am Donnerstag, Januar 25, 2024 12:43 CET, schrieb Timrov Iurii <iurii.timrov at psi.ch>:

> Dear Simon,
> 
> If you check the output file of the second SCF calculation, you will see this:
>  highest occupied, lowest unoccupied level (ev):    13.2680   12.9953
> 
> This means that the system is metallic, and hence your should not use a two-step SCF procedure. Just perform the first SCF calculation with smearing and then proceed to the HP calculation. Or, if the system is experimentally known to be insulating, you can add some finite value of U to V-3d states, which should open a gap and then proceed with the two-step SCF procedure plus HP.
> 
> HTH
> 
> Iurii
> 
> ________________________________
> From: users <users-bounces at lists.quantum-espresso.org> on behalf of Simon Imanuel Rombauer <simon.rombauer at student.uni-augsburg.de>
> Sent: Wednesday, January 24, 2024 20:42
> To: users at lists.quantum-espresso.org <users at lists.quantum-espresso.org>
> Subject: [QE-users] hp.x Error in routine cdiaghg (270): problems computing cholesky
> 
> Dear QE users,
> 
> for some time I am trying to find  suitable DFT+U+V parameters for orthorhombic LaVO3 band structure. I was limited with with computational resources so I tried to manually tune the parameters to match experimental band gab. This was very tedious and most calculations did not converge at all. Now I have more CPU cores to work with and want to use the hp.x code to calculate them using DFPT. I followed example 02 and 06 from the documentation, that is I first calculated scf of LVO using a smearing and starting mag. and then did a second scf run with fixed occupation and total mag. = 0. Then I split the HP calculation for each perturbed atom. It always ends with Error in routine  cdiaghg (270):       problems computing cholesky, I have tried to change mixing_mode, mixing_beta, higher ecutwfc and ecutrho, lowered the conv_thr but nothing worked. (input/output files appended)
> 
> Any idea is highly appreciated, also on how to speed up calculations, it still seems rather slow when calculating scf.
> All the best and have a nice day
> 
> Simon Rombauer
> Master Student Physics
> University Augsburg
> Germany
> 
> PS: I manually changed the occupation in the La PP from 5d to 4f, but even when I left the PP as it is and simply tried to calculate U for La-5d it crashed with the same error.