Basis Sets for Spin-Orbit

[Ehsangowdini]

Dear Crystal Team
Hi

I was wondering If I can use the TZVP_rev2 basis set posted in the official website of CRYSTAL for Mg and Si atoms for SOC calculation ?

e.g.
Mg_pob_TZVP_rev2

12 9
0 0 7 2.0 1.0
31438.3495550 0.00060912311326
4715.51533540 0.00470661964650
1073.16292470 0.02413582065700
303.572387680 0.09362895983400
98.6262510420 0.26646742093000
34.9438084170 0.47890929917000
12.8597851990 0.33698490286000
0 0 3 2.0 1.0
64.8769130040 0.01918088930700
19.7255207770 0.09091370439200
2.89518043390 -0.39563756125000
0 0 2 2.0 1.0
1.19604547100 1.68276033730000
0.54329451156 0.52141091954000
0 0 1 0.0 1.0
0.83471188300 1.00000000000000
0 0 1 0.0 1.0
0.14506887000 1.00000000000000
0 2 5 6.0 1.0
179.871896120 0.00537995490180
42.1200693760 0.03931801409800
13.1205030320 0.15740129476000
4.62575036090 0.35919094128000
1.66952110160 0.45533379310000
0 2 1 0.0 1.0
0.56631001000 1.00000000000000
0 2 1 0.0 1.0
0.18813966000 1.00000000000000
0 3 1 0.0 1.0
0.29355357000 1.00000000000000

[GiacomoAmbrogio]

Hi Ehsangowdini,
Could you please share an example of your input file?

[Ehsangowdini]

MgSiPt3_PBE_soc.d12

Sure
Here is the input for SOC

Thank you so much

[GiacomoAmbrogio]

There shouldn't be any problem in using POB basis sets alongside a basis set with ECP for SOC.
If you run into any issues, send the output file and I’ll take a closer look.

[Ehsangowdini]

Thank you so much for responding
The manual states, "Only the FR COLUSC, COLULC, COLUSH, STUTSC, STUTLC, and STUTSH libraries include spin-orbit SOREP operators in their definition." I was wondering if I can use the POB basis sets for SOC as well? In other words, if I use POB basis sets, do I still get the accurate effect of SOC on the bands?

[aerba]

Hi,

In the current implementation in CRYSTAL, SOC is described through relativistic effective core pseudo-potentials (RECPs) and thus is not included if all-electron basis sets are used.

However, there are two important points to be stressed:

1. It is possible to run a SOC calculation where RECPs are used on a subset of elements while all-electron basis sets are used on remaining atoms (this is the case of the input file you initially shared, where you had RECPs on Pt and all-electron basis sets for Mg and Si).

2. Some POB basis sets (i.e. those of heavy elements) do make use of RECPs that can be used for SOC calculations in CRYSTAL. These basis sets are labeled with a _SOC at the end of their name. Please, refer to this page:

https://www.crystal.unito.it/basis_sets.htm

By clicking on an element (Iodine for instance), you'll get the list of available basis sets already in CRYSTAL format:

In this example, the last one is a POB basis set that can be used for SOC calculations.

Hope this helps

[Ehsangowdini]

Thank you so much
this helped a lot