I am planning to use the finite displacement method for calculating phonon spectrum, and I have prepared the INCAR file below to try it on a transition metal trihalide monolayer (e.g., VI$_3$). I would be very grateful if you could please check it and tell me what I should add/omit, and if you recommend following this Phonopy tutorial.
NPAR = 6 # Self Consistent Calculation step: ISTART = 0 ICHARG = 2 #Electronic Relaxation: ENCUT = 550 eV EDIFF = 1.0E-8 PREC = Accurate LREAL = .FALSE. IALGO = 38 ADDGRID=.TRUE. LCHARG = .FALSE. LWAVE = .FALSE. #Phonons IBRION = -1 #Relaxation: ISMEAR = 0 SIGMA = 0.05 NSW = 1 GGA_COMPAT = .FALSE. # Magnetism: ISPIN= 2 MAGMOM = 4*-5.0 4*5.0 24*0.6 LASPH = .TRUE. LMAXMIX = 4 VOSKOWN = 1 #Mixer AMIX = 0.2 BMIX = 0.00001 AMIX_MAG = 0.8 BMIX_MAG = 0.00001
I am a little bit confused about which IBRION tag to use (IBRION=-1 or IBRION=6)