Menu

Atomic volumes of Actinoids

Elk Users
2021-09-14
2021-09-22
  • Malte Sachs

    Malte Sachs - 2021-09-14

    Dear all,

    I have calculated the atomic volumes of the actinoids from the EOS of bcc-cells, non-magnetic, with and without SOC ( primary to test pseudopotentials I have created.). However, I am quite surprised that beyond Am the SOC results deviate so strongly from the scalar-relativistic calculations (see file attached). All EOS curves look smooth. I have fixed the MT-radius to the smallest used volume. My PAW calculations show a similar trend, however deviate more strongly above Am from the Elk calculations. Unfortunately, all references I can find in the web are dealing with the light actinoides. So I don't know if my results are reliable or if I have missed something in the input file. Does anyone has an idea?

    Best regards,
    Malte

    Here is an example of an input file:

    tasks
    0

    avec
    0.5 0.5 0.5
    -0.5 0.5 0.5
    -0.5 -0.5 0.5

    scale1
    7.11378660898

    scale2
    7.11378660898

    scale3
    7.11378660898

    scale
    1.06

    xctype
    20

    sppath
    './'

    rgkmax
    9.5

    gmaxvr
    18

    lmaxapw
    10

    lmaxo
    8

    lradstp
    2

    msmooth
    4

    nempty
    15

    autolinengy
    .true.

    stype
    1

    swidth
    0.01

    mixtype
    3

    broydpm
    0.3 0.12

    epspot
    1.E-06

    epsengy
    1.E-05

    spinpol
    .false.

    spinorb
    .true.

    atoms
    1 : nspecies
    'Md.in' : spfname
    1 : natoms
    0.0 0.0 0.0 0.0 0.0 0.0 : atposl, bfcmt

    ngridk
    15 15 15

     
  • Malte Sachs

    Malte Sachs - 2021-09-14

    Sorry: in the key the SR and SOC results have to be changed!

     
  • Anton F.

    Anton F. - 2021-09-22

    Hi, Malte,
    I think these peculiarities in your plot are related to the complicated nature of 5f states in actinides, which are believed to change their behavior from transition metals-like to rare earth metals-like exactly at Am - you can have a look at this review http://dx.doi.org/10.1103/RevModPhys.81.235
    Actinides are also known to be systems, where SOC is important (because these are heavy elements and jj-type coupling dominates), so there is no wonder your scalar relativistic calculations and the ones including SOC are different.
    In addition, one should remember that 5f electrons in actinide metals are strongly correlated and e.g. DFT+U corrections should be considered when calculating the ground state of an actinide.
    Best regards,
    Anton F.

     

Log in to post a comment.