The ABINIT Users Mailing List ( CLOSED )

[thanusit@kku.ac.th]

Dear Abinit users

I tried to calculate the GW corrections(using plasmon pole model) for a 
metallic alloy Ga4P3Ti. In a convergence test of the GW corrections at Gamma, 
I got the results as shown below. Please note the E0 values. The calculation 
was done using Abinit 5.4.3., both Parallel and sequencial version. Results 
are the same.

-------------------------------------------
 Perturbative Calculation

 k =    0.000   0.000   0.000
 Band     E0 <VxcLDA>   SigX SigC(E0)      Z dSigC/dE  Sig(E)    E-E0       E
   36   0.145 -12.115  -8.696   0.484   0.893  -0.120  -8.628   3.487   3.632
   37   0.913  -9.582  -3.039  -2.806   0.925  -0.081  -6.125   3.457   4.370

 E^0_gap          0.000
 E^GW_gap         3.487
 DeltaE^GW_gap    3.487
-------------------------------------------

From the ground state band calculation, there is a clear separation between 
band 36 and 37. I wonder  why "E^0_gap" is reported "0.000", instead of 
0.768eV (equals to 0.913-0.145 eV).

I looked through the "occ" variables. They indicate that, for this metalic 
alloy, band 36 is half-filled while band 37 is empty. Does the above result 
have anything to do with the half-filled metalic character?

Regards, 

Thanusit Burinprakhon


##Input Files##

ndtset 15

# Calculation of the Self-Energy matrix elements (GW corrections)

optdriver    4        
getkss       1         
getscr       1        
nband        80      

##variable for convergence test
ecutwfn: 5.0         
ecutwfn+ 5.0          

ecutsigx 10.0       
nkptgw   1           
kptgw    0.0 0.0 0.0  
bdgw     36 37       

ecut  100            
acell  3*10.5056      
rprim  1.0  0.0 0.0   
       0.0  1.0 0.0   
       0.0  0.0 1.0 
ntypat 3         
znucl 22 15 31
natom 8
typat 1 2 2 2 3 3 3 3
xred
     0.0000000000E+00  0.0000000000E+00  0.0000000000E+00
     5.0000000000E-01  5.0000000000E-01  0.0000000000E+00
     5.0000000000E-01  0.0000000000E+00  5.0000000000E-01
     0.0000000000E+00  5.0000000000E-01  5.0000000000E-01
     2.5979480250E-01  2.5979480250E-01  2.5979480250E-01
     2.5979480250E-01  7.4020519750E-01  7.4020519750E-01
     7.4020519750E-01  2.5979480250E-01  7.4020519750E-01
     7.4020519750E-01  7.4020519750E-01  2.5979480250E-01
 
nstep 100 
diemac 12.0        
nsym 0        
symmorphi 0
ixc 7
iscf 5
prtvol 1