cbas for relativistic two-component all-electron GW calculation

[martijn]

Hi,

If I want to run a relativistic two-component all-electron GW calculation on a molecule containing elements for which the normal basis-set has an ECP, e.g. Cd, how do I choose the cbas?

For the ground-state DFT (using $soghf, $kramers and $rx2c) I use x2c-SVPall-2c as basis and that basis-set is also available for jbas but not cbas.

Thanks,

Martijn

[chris.hol]

Hi Martijn,

for the all-electron x2c-SVPall-2c basis sets specialized cbas-type auxiliary basis sets unfortunately do not yet exist (as far as I know however they are being worked on, but not by me. : ) ). The quickest solution is therefore to use the jbas also as cbas. This has to be done manually as of version 7.5. Under linux these two command lines should achieve this:

sed -ie 's/jbas/cbas/g' auxbasis
sed -ie 's/jbas/cbas/g' control

They change all occurrences of "jbas" in the auxbasis and control file to "cbas". For escf alone this is enough. In case you want to re-add the according jbas (to be able to run ridft in case it was not already done), just proceed a second time through define and the "ri" menu in the final section. This will re-add the jbas. As the jbas basis for the x2c basis set is fairly large I do not expect enlarged errors by using the jbas also in the GW procedure.

In case you perform two-component calculations using the dhf-SVP-2c (or higher) basis set family, using the def2-SVP/def2-TZVP etc cbas is fine.

All the best,
Christof

[martijn]

Thanks Christof. That works other than that next the G0W0 calculation crashes with the following error message:

           ----------------------
               RI - INFORMATION
           ----------------------

 biggest AO integral is expected to be    32.038321512

 Threshold for integral neglect (rithr2):   0.89E-11
 Threshold for integral neglect (rithr1):   0.89E-11

 Contributions to RI integral batches:
  neglected integral batches:                  1364
  direct contribution:                            0
  memory contribution:                  4964
 Core memory available (ricore)            500 MiB
 Core memory needed for (P|Q) and Cholesky 0 MiB
 Core memory used for integrals            0 MiB
 
 ****************************************
 Memory allocated for RIDFT 0 MiB
 ****************************************
                                           
  lit,ljt,lkt:                     4                     4                     0

========================
 internal module stack:
------------------------
    escf
    lpdrec
========================

 l-qun in <asrstat> messy
 escf ended abnormally

Do you know what the origin of that might be? I assume that is not because of using the jbas for the cbas.

Thanks,

Martijn

P.S. this is the GW bit of control:

$scfinstab soghf
$soes all
$rpacor   22000
$rick
$rigw
  rpa
  mxdiis       8
  npoints    128
  npade      128
  rpoints     16
  rshift    0.20000000
  ips+     1
  gap
  eta       0.00100000

[chris.hol]

Hi Martijn,

hm, this seems to be unrelated to the G0W0 step, rather it may be an error while reading in/processing the auxiliary basis set. Can you check the beginning of the output for the basis section; specifically the last occurrence of this one:

 AUXILIARY BASIS SET information:

              we will work with the 1s 3p 5d 7f 9g ... basis set
              ...i.e. with spherical basis functions...

   type   atoms  prim   cont   basis
   ---------------------------------------------------------------------------
    cd       1    131    131   x2c-SVPall-2c   [25s5p5d3f5g|25s5p5d3f5g]
   ---------------------------------------------------------------------------
   total:    1    131    131
   ---------------------------------------------------------------------------

and check if the readout there makes sense in your calculation? Unfortunately I could not reproduce this error with any version I have available, and this error is not familiar to me. But the last line printed out (lit,ljt,lkt: ) suggests that the auxiliary basis set is weird/invalid - the numbers report f-orbitals for the orbital basis set ( first two numbers = 4, matching for the x2c-SVPall-2c basis set) but 0 for the auxiliary index, which means lower than an s-orbital. Maybe something went wrong using the stream editor :/.

All the best,
Christof

[martijn]

Thanks Christof. I'll check.

It was likely a fluke as since Friday I have been successfully able to run 2c-GW calculations for other systems using your cbas fix.

Best,

Martijn

[chris.hol]

Hi Martijn,

good to that it works at least for some other systems! Most likely something broke in the auxbasis/control file at some point for the Cd system, maybe an unlucky combination of coincidents and stream editors.

All the best,
Christof