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Hi
I have a big problem in the calculations of total energy of bulk CU2O in HSE06+ISPIN=2. As we all known, CU2O is a non-magnetic system. Therefor there should be no differences in total energies when we add ISPIN=2 or not. However, when I add ISPIN=2 or not, my values of this system is-169.67ev and -18.775 ev, respectively. All my INCAR, POSCAR, KPOINTS, POTCAR are the same, expect add ISPIN=2 in INCAR when I consider the spin polarization. I tried a lot but all failed. My INCAR is as follows,
PREC = Accurate
ISTART = 1
ISMEAR = 0
SIGMA = 0.05
EDIFF = 1E-4
ENCUT = 400

NELMIN = 5
LREAL = A
NBANDS = 36
ALGO = Damped
NPAR = 36

LWAVE = .F.
LCHARG = .F.

#HSE06
LHFCALC = .T.
HFSCREEN = 0.2
TIME = 0.4
PREFOCK = Normal
AEXX = 0.275
LDIAC = .T.
ISPIN = 2
Could anybody help me. Thank you very much!

Using restart (ISTART=1) makes you dependent on the previous calculation.
Try to perform both calculations with ISTART=0.

Thank you for your reply. I have tried both the ISTART=0 and 1, but the results were all the same.
my KPOINTS is as follows:
Automatic
0
Monkhorst-Pack
5 5 5
0 0 0

POSCAR:
CIF file
1.00000000000000
4.2695999145999997 0.0000000000000000 0.0000000000000000
0.0000000000000000 4.2695999145999997 0.0000000000000000
0.0000000000000000 0.0000000000000000 4.2695999145999997
Cu O
4 2
Direct
0.2500000000000000 0.2500000000000000 0.2500000000000000
0.7500000000000000 0.7500000000000000 0.2500000000000000
0.7500000000000000 0.2500000000000000 0.7500000000000000
0.2500000000000000 0.7500000000000000 0.7500000000000000
0.0000000000000000 0.0000000000000000 0.0000000000000000
0.5000000000000000 0.5000000000000000 0.5000000000000000

0.00000000E+00 0.00000000E+00 0.00000000E+00
0.00000000E+00 0.00000000E+00 0.00000000E+00
0.00000000E+00 0.00000000E+00 0.00000000E+00
0.00000000E+00 0.00000000E+00 0.00000000E+00
0.00000000E+00 0.00000000E+00 0.00000000E+00
0.00000000E+00 0.00000000E+00 0.00000000E+00

POTCAR:
parameters from PSCTR are:
VRHFIN =Cu: d10 p1
LEXCH = 91
EATOM = 1393.0707 eV, 102.3878 Ry


parameters from PSCTR are:
VRHFIN =O: s2p4
LEXCH = 91
EATOM = 433.0277 eV, 31.8266 Ry

Could you help me point out my mistakes and thank you very much!

Hi,

what is the initial guess of your ISPIN=2 calculation like?

You could also use
ALGO = N
for a change.

Cheers,

alex

Thank you for your attention. I adopted your advice and tried ALGO=Normal in my INCAR, but still failed. The total energy is still the same as before. I think it may be another mistakes in my calculations.
If convenient, could anyone help me calculate my example in your server and find if this mistake is still in your calculations. Could you give me your email and I will give your my input files. My email is 18761792087@163.com. Thank you very much.