Dear all,
I am doing relaxation calculation in VASP for a material BaLaMn2O6. I am confused for how to choose the DFT +U input for the calculation(Single point energy calculation , band structure ) .What should i choose LMAXMIX if i have to apply hubbard correction to both the rare earth elements(Y,Ce,Pr,Dy,etc) and the transition elements(Fe,Cr,Mn..) ? In vaspwiki it is mentioned that LMAXMIX is 4 for d-elements and 6 for f-elements.But I have both.here i am attachng the INCAR file .....
Global Parameters
ISTART = 1 (Read existing wavefunction; if there)
# ISPIN = 2 (Spin polarised DFT)
# ICHARG = 11 (Non-self-consistent: GGA/LDA band structures)
LREAL = Auto (Projection operators: automatic)
ENCUT = 600 (Cut-off energy for plane wave basis set, in eV)
PREC = High (Precision level)
LWAVE = .TRUE. (Write WAVECAR or not)
LCHARG = .TRUE. (Write CHGCAR or not)
ADDGRID= .TRUE. (Increase grid; helps GGA convergence)
# LVTOT = .TRUE. (Write total electrostatic potential into LOCPOT or not)
# LVHAR = .TRUE. (Write ionic + Hartree electrostatic potential into LOCPOT or not)
# NELECT = (No. of electrons: charged cells; be careful)
# LPLANE = .TRUE. (Real space distribution; supercells)
# NPAR = 4 (Max is no. nodes; don't set for hybrids)
# NWRITE = 2 (Medium-level output)
# KPAR = 2 (Divides k-grid into separate groups)
# NGX = 500 (FFT grid mesh density for nice charge/potential plots)
# NGY = 500 (FFT grid mesh density for nice charge/potential plots)
# NGZ = 500 (FFT grid mesh density for nice charge/potential plots)
EDIFF = 1.0E-06
ALGO=Fast
Lattice Relaxation
NSW = 55 (number of ionic steps. Make it odd.)
ISMEAR = 0 (gaussian smearing method )
SIGMA = 0.05 (please check the width of the smearing)
IBRION = 2 (Algorithm: 0-MD; 1-Quasi-New; 2-CG)
ISIF = 2 (optimize atomic coordinates and lattice parameters)
EDIFFG = -1.0E-03 (Ionic convergence; eV/AA)
PREC = High (Precision level)
LDAU = True #switches on DFT+U
LDAUJ = 0 0 0 0 # J values (For LDAUTYPE=2 , Ueff = U-J)
LDAUL = 3 -1 2 -1 #l-quantum number (-1 : no U,
LDAUPRINT = 1 # 0:silent, 1: write occupancy matrix to OUTCA,
LDAUTYPE = 2 #The simplified approach to the DFT+U , introduced by Dudarev et al.
LDAUU = 4.0 0 3.0 0 # for La :4.0 , Ba:0 , Mn:3.0, O:0 ( U values in eV)
LMAXMIX = 6 # 4 for d-electrons, 6 for f-electrons
LASPH = .TRUE.
and the POSCAR file too..
generated by phonopy
1.0
3.9178000000000002 0.0000000000000000 0.0000000000000000
0.0000000000000000 3.9178000000000002 0.0000000000000000
0.0000000000000000 0.0000000000000000 7.8070000000000004
La Ba Mn O
1 1 2 6
Direct
0.0000000000000000 0.0000000000000000 0.0000000000000000
0.0000000000000000 0.0000000000000000 0.5000000000000000
0.5000000000000000 0.5000000000000000 0.7548999999999999
0.5000000000000000 0.5000000000000000 0.2451000000000001
0.5000000000000000 0.5000000000000000 0.0000000000000000
0.0000000000000000 0.5000000000000000 0.7626999999999999
0.5000000000000000 0.0000000000000000 0.7626999999999999
0.0000000000000000 0.5000000000000000 0.2373000000000001
0.5000000000000000 0.0000000000000000 0.2373000000000001
0.5000000000000000 0.5000000000000000 0.5000000000000000
Sorry if the Post is lengthy , It's just for elaboration of my doubt. Any suggestion is highly appreciated. Thank You !!
In vasp wiki, you will see LMAXMIX = [integer].
[integer] means you can set a list of integer for each element.
For example, LMAXMIN= 4 4 6 6 means d for the first two element, f for the last two element.
Wang Jinkai Thank you for your response. I was thinking that one can only use either 4 or 6 for LMAXMIX . Could you please attach a INCAR file DFT+U where both d-electrons and f-electrons are treated ?
Thank you !!
I think I have written clearly.
La Ba Mn O is the element in your POSCAR.
Setting LMAXMIN= 4 4 6 6 in incar (for example) means treating d for La and Ba, treating f for Mn and O.
Wang Jinkai But O doesn't have f-electrons . what should i use for O ?
In this example Constraining the local magnetic moments - Vaspwiki, you will see that the official site set the LMAXMIN=4 for both Ni and O, so you can also set 4 for O and this will have no effect on the O electrons behavious as you said O has no d or f electrons.
Wang Jinkai Thank you !! Got your point I will try all the steps you have suggested . Thank you once again.
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