NF₂: spin-other-orbit contribution g-tensor

Sample directory: adf/EPR_SOO

In this example the spin-other-orbit contribution to the g-tensor G(SOO) is calculated with the EPR module.

The NMR/EPR program gives functionality that partially overlaps and partially differs from the ESR keyword inside ADF. Please check the ADF and Property Programs User's Guides for details. The spin-other-orbit contribution to the g-tensor is not something that can be calculated with the ESR option inside ADF.

The preparatory ADF calculation can run parallel, the EPR module should run serial. The ADF calculation should use symmetry NOSYM, and an all electron basis set is required for the calculation of the G(SOO) term. TAPE10 is saved, which is necessary if special XC-potentials are used, like SIC or SAOP.

$ADFBIN/adf << eor
Unrestricted
Charge 0 1
Atoms
  N       0.000000      0.000000      0.611280
  F       0.000000     -1.090100     -0.237720
  F       0.000000      1.090100     -0.237720
END
XC
  GGA Becke Perdew
END
Basis
 Type DZ
 Core None
End
Symmetry NOSYM
SAVE TAPE10, TAPE15
eor

The EPR calculation itself then has a fairly simple input. It uses the TAPE21, TAPE10, and TAPE15 files generated by ADF. The full EPR G-tensor is printed, including an extensive analysis for the contribution of different terms, including the (small) spin-other-orbit contribution to the g-tensor G(SOO).

The spin-other-orbit contribution to the g-tensor G(SOO) is calculated by including the subsubkey SOO in the subkey EPRGT of the key CLGEPR. Note that the calculation can take very long, if one uses a larger basis set, and a better integration grid. Both are in fact necessary for reliable results.

$ADFBIN/epr -n1 << eor
CLGEPR
  EPRGT
    SOO
  SUBEND
  NUCLEI NONE
  OUTPUT
    EPRSIZE LARGE
  SUBEND
END
END INPUT
eor