Platinum(111) surface. total energy calculation

Message

neogien · #1 Post by **neogien** » Thu Dec 14, 2006 2:30 pm

Hi everyone.

I had completed the relaxation of Pt (111) surface (there is my previous question dealed with it below).

Now I just finished calculation on the total energy of relaxed surface(slab) owing to know the reference energy for atomic or molecular adsorptions.

During surface relaxation, the mag value had converged to 0. I think it is natural. However, after total energy calculation I founed that the mag value in OSZICAR file was higher than 1 (6.7xx, I performed ISPIN=2 calculation).

What is the problem?
Should I restrict the NUPDOWN value to 0 manually, to make mag value to 0?? Or can I just neglect it?
The high mag value means there are some problems in optimized slab structure?
Is this a natural result caused by setting ISMEAR to -5 ??

I'm attaching my INCAR and OSZICAR file.

--------------------INCAR-------------------------
System = Pt 3x3x4
ENMAX = 400
ISMEAR = -5
SIGMA = 0.2
GGA = RP
ISPIN = 2

NSW = 0
IBRION = -1
ISIF = 2

ALGO = fast
LREAL = A
POTIM = 0.02

LORBIT = 11
LCHARG=.FALSE
LWAVE=.FALSE

------OSZICAR-------------
DAV: 1 0.340225118022E+04 0.34023E+04 -0.13154E+05 4808 0.109E+03

DAV: 2 0.124279599260E+03 -0.32780E+04 -0.29634E+04 4912 0.425E+02

DAV: 3 -0.165000821581E+03 -0.28928E+03 -0.26012E+03 5880 0.112E+02

DAV: 4 -0.179798837649E+03 -0.14798E+02 -0.13957E+02 6152 0.285E+01

DAV: 5 -0.180079604355E+03 -0.28077E+00 -0.27966E+00 6232 0.330E+00 0.246E+01
RMM: 6 -0.168022646075E+03 0.12057E+02 -0.35288E+01 5079 0.178E+01 0.177E+01
RMM: 7 -0.172963709639E+03 -0.49411E+01 -0.16083E+01 5111 0.930E+00 0.237E+01
RMM: 8 -0.158645997213E+03 0.14318E+02 -0.51512E+00 5027 0.537E+00 0.762E+00
RMM: 9 -0.158683643781E+03 -0.37647E-01 -0.86580E-01 5184 0.170E+00 0.720E+00
RMM: 10 -0.159573857126E+03 -0.89021E+00 -0.33584E-01 5375 0.124E+00 0.967E+00
RMM: 11 -0.159951902758E+03 -0.37805E+00 -0.94222E-01 5033 0.234E+00 0.450E+00
RMM: 12 -0.161511463316E+03 -0.15596E+01 -0.34310E-01 5020 0.118E+00 0.394E+00
RMM: 13 -0.162967125492E+03 -0.14557E+01 -0.45788E-01 4943 0.127E+00 0.311E+00
RMM: 14 -0.166582401822E+03 -0.36153E+01 -0.19691E+00 4883 0.197E+00 0.174E+00
RMM: 15 -0.168460842339E+03 -0.18784E+01 -0.13662E+00 4982 0.142E+00 0.989E-01
RMM: 16 -0.168664262298E+03 -0.20342E+00 -0.17983E-01 5193 0.611E-01 0.406E-01
RMM: 17 -0.168672484957E+03 -0.82227E-02 -0.27150E-02 5185 0.317E-01 0.234E-01
RMM: 18 -0.168702147756E+03 -0.29663E-01 -0.17120E-02 5088 0.205E-01 0.136E-01
RMM: 19 -0.168732496537E+03 -0.30349E-01 -0.61479E-03 4694 0.129E-01 0.812E-02
RMM: 20 -0.168754494555E+03 -0.21998E-01 -0.61103E-03 4543 0.128E-01 0.540E-02
RMM: 21 -0.168770785552E+03 -0.16291E-01 -0.35079E-03 4163 0.854E-02 0.299E-02
RMM: 22 -0.168779887072E+03 -0.91015E-02 -0.17382E-03 3907 0.693E-02 0.212E-02
RMM: 23 -0.168786410607E+03 -0.65235E-02 -0.84236E-04 3598 0.503E-02 0.134E-02
RMM: 24 -0.168789422264E+03 -0.30117E-02 -0.35625E-04 3327 0.325E-02 0.814E-03
RMM: 25 -0.168789778397E+03 -0.35613E-03 -0.15835E-04 3116 0.229E-02 0.496E-03
RMM: 26 -0.168789857748E+03 -0.79351E-04 -0.70778E-05 2814 0.157E-02

1 F= -.16878986E+03 E0= -.16878986E+03 d E =0.000000E+00 mag= 6.7341

<span class='smallblacktext'>[ Edited ]</span>

#2 Post by **admin** » Fri Dec 15, 2006 2:37 pm

so, what did you actually do in that last run?

neogien · #3 Post by **neogien** » Wed Dec 20, 2006 3:37 am

I had tried to get reference energy (total energy) of optimized Pt(111) slab system. Because I had found a mention that Ismear=-5 is more reliable to calculate total energy of system so I had used it.

After posting this question I also tested with Ismear = 1.
The mag value was converged to 0.