[Pw_forum] hyperfine calculation

[Jones Tsz-Kai Wan]

Dear pwscf users

Does anyone here have experience on HF calculation using gipaw?

I made extensive test on hyperfine tensor calculation using the gipaw
code, and I couldn't get reasonable result except free hydrogen atom.
For H atom, the Fermi contact term (A_s) obtained (~1480) is within
10% of published work [e.g. Van de Walle and Blochl, PRB 47, 4244
(1993)]. However, the results for Si is unreasonable. The Fermi
contact is only ~ 1% of the published data, and the dipole term (A_p)
is zero, which is impossible.

Jones Wan

Published result:
A_s ~ 1400 for H, A_s ~ -4200 and A_p ~ -100 [Van de Walle, PRB 47,
4244 (1993)].

My calculation results:

HF of H:

 H    1: g_n =  5.585693                  MHz
 H    1  hfi_dipole       0.000000       0.000000       0.000000
 H    1  hfi_dipole       0.000000       0.000000       0.000000
 H    1  hfi_dipole       0.000000       0.000000       0.000000

 H    1  hfi_dipole       0.000000       0.000000       0.000000

Fermi contact term:        bare     reconstruction      total
                         0.000000    1484.328021    1484.328021
 **** ZORA ****
                         0.000000    1485.026008    1485.026008

HF of Si:

 Si   1: g_n = -1.110574                  MHz
 Si   1  hfi_dipole       0.000000       0.000000       0.000000
 Si   1  hfi_dipole       0.000000       0.000000       0.000000
 Si   1  hfi_dipole       0.000000       0.000000       0.000000

 Si   1  hfi_dipole       0.000000       0.000000       0.000000

Fermi contact term:        bare     reconstruction      total
                         0.000000      45.266354      45.266354
 **** ZORA ****
                         0.000000      42.470825      42.470825