SOC Effects
SOC
lspinorb
is used for control whether or not SOC(spin-orbit coupling) effects should be considered.
Both basis_type=pw
and basis_type=lcao
support scf
and nscf
calculation with SOC effects.
Atomic forces and cell stresses can not be calculated with SOC effects yet.
Pseudopotentials and Numerical Atomic Orbitals
For Norm-Conserving pseudopotentials, there are differences between SOC version and non-SOC version.
Please check your pseudopotential files before calculating. In PP_HEADER
part, keyword has_so=1
and relativistic="full"
refer to SOC effects have been considered, which would lead to different PP_NONLOCAL
and PP_PSWFC
parts. Please be careful that relativistic="full"
version can be used for SOC or non-SOC calculation, but relativistic="scalar"
version only can be used for non-SOC calculation. When full-relativistic pseudopotential is used for non-SOC calculation, ABACUS will automatically transform it to scalar-relativistic version.
Numerical atomic orbitals in ABACUS are unrelated with spin, and same orbital file can be used for SOC and non-SOC calculation.
Partial-relativistic SOC Effect
Sometimes, for some real materials, both scalar-relativistic and full-relativistic can not describe the exact spin-orbit coupling. Artificial modulation can help for these cases.
soc_lambda
, which has value range [0.0, 1.0] , is used for modulate SOC effect. In particular, soc_lambda 0.0
refers to scalar-relativistic case and soc_lambda 1.0
refers to full-relativistic case.