penalty energy in constrained noncollinear magnetic calculations
Posted: Fri Sep 09, 2011 7:34 pm
Dear all,
I have followed the VASP handsonIV file (http://cms.mpi.univie.ac.at/vasp-worksh ... dsonIV.pdf) to do noncollinear calculations for a Fe dimer. I want to understand the penalty energy E_p in OSZICAR.
If I set MAGMOM = 0 0 3 0 0 3, I can get FM configuration. If I set MAGMOM = 0 0 3 0 2 2, and want to maintain such configuration during relaxation, I have to set
I_CONSTRAINED_M = 1
RWIGS = 1.0
LAMBDA = 10
M_CONSTR = 0 0 1 0 1 1
Then I get "E_p = 0.35424E-02" in OSZICAR. I understand E_p contributes to the total energy.
Is E_p for each Fe atom or both atoms? If I deduct E_p from the total energy, can I get the energy for the Fe dimer with magnetic configuration (0 0 3, 0 2 2).
If I do not use the constraint, the relaxation will always give me the FM configuration. I want to know the system's total energies for other magnetic configurations such as (0 0 3, 0 2 2). Can I get there by just subtracting the E_p from the total energy?
Thanks.
Leo
I have followed the VASP handsonIV file (http://cms.mpi.univie.ac.at/vasp-worksh ... dsonIV.pdf) to do noncollinear calculations for a Fe dimer. I want to understand the penalty energy E_p in OSZICAR.
If I set MAGMOM = 0 0 3 0 0 3, I can get FM configuration. If I set MAGMOM = 0 0 3 0 2 2, and want to maintain such configuration during relaxation, I have to set
I_CONSTRAINED_M = 1
RWIGS = 1.0
LAMBDA = 10
M_CONSTR = 0 0 1 0 1 1
Then I get "E_p = 0.35424E-02" in OSZICAR. I understand E_p contributes to the total energy.
Is E_p for each Fe atom or both atoms? If I deduct E_p from the total energy, can I get the energy for the Fe dimer with magnetic configuration (0 0 3, 0 2 2).
If I do not use the constraint, the relaxation will always give me the FM configuration. I want to know the system's total energies for other magnetic configurations such as (0 0 3, 0 2 2). Can I get there by just subtracting the E_p from the total energy?
Thanks.
Leo