The ABINIT Users Mailing List ( CLOSED )

["Zhenhua Zeng" <myid520@163.com>]

Dear All,

I want to have PAW calculation of Platinum (Pt). But abinit does not provide 
the PAW potential of Pt.
So I try to generate it myself. For the tested physical parameter, I also 
refer to the following reference:
M. Korling, J. Haglund, Phys. Rev. B 45, 13293 (1992)
In this reference, structural parameters for FCC Pt in the GGA approximation 
are:
a0 = 7.65 a.u.
B0 = 232 GPa

Following the lesson PAW2, I test the parameters rc, rcloc, lloc, rpcor.
But I find that, if nbeta=6, no matter how to tune the parameters, either a0 
or B0 has great discrepancy with the reference values (Is this the reason why 
PAW potential of Pt is not provided).
So, I decide to generate the potential base on the parameters of compos in 
the following.
The all-electron input file and the generation file are not changed except 
rc, rcloc, lloc rpcor and ibeta=3.
Through tuning I find the optimal parameters are rc=2.0, 
rcloc=2.0,rpcor=1.2,lloc=0. And the results for the optimal parameters are
a0 = 7.682 a.u.
B0 = 231.6 GPa.
The optimal generation file is given below.

Using generated Ultra-Soft Pseudo-Potential when generating PAW potential, 
Dacapo give the following results:
a0 = 7.55 a.u.
B0 = 254 GPa.

The other GGA results of a0 are
7.54 a.u for Wien2k,
7.538 a.u for VASP PAW,
7.56 a.u for Dacapo USPP
(Feibelman, P. J., Hammer, B., Norskov, J. K., Wagner, F., Scheffler, M., 
Stumpf, R., Watwe, R. & Dumesic, J. The CO/Pt(111) puzzle. Journal of 
Physical Chemistry B 105, 4018-4025 (2001).).

We can find that, for a0, there is about 2% discrepancy between my PAW result 
and the other GGA results.
So, I want to know whether the PAW potential I generate can be used for 
prediction or not.
I also want to if there have some more experienced users who have generated 
more consistent PAW potential with other GGA results.
Your help is greatly appreciated!

-----------------Generation file-----------------------------
    0    2    1    1    3           ifae,ifpsp,ifprt,ifplw,ilogd (5i5)
   2.6     -4.       2.       80    rlogd,emin,emax,nnt (3f10.5,i5)
   1.0d-11   1.0d-09   0.5          thresh,tol.damp (2e10.1,f10.5)
pt                                  title (a20)
   12   3    3                      ncores,nvales,nang (3i5)
 10.0     20.0     50.0      10.0       besrmax,besemin,besemax,besde(4f10.5)
    3    1   1.0      1.20          keyps,ifpcor,rinner rpcor(2i5,f10.5)
    3   2.20                        nbeta,rcloc (i5,f10.5)
   2.20       2.20       2.20       rc (3f10.5)
    1   3   0.0       2             lll,keyee,eeread,iptype (2i5,f10.5,i5)
    2   1   0.0       2             lll,keyee,eeread,iptype (2i5,f10.5,i5)
    2   0   0.2       2             lll,keyee,eeread,iptype (2i5,f10.5,i5)
    8  10.0
    0   2   0.00000   3             lloc,keyee,eloc,iploctype (2i5,f10.5,i5)
    3   8   10.0                    ifqopt,nqf,qtryc (2i5,f10.5), 


        

Best wishes                     

Zhenhua Zeng
Dalian Institute of Chemical Physics, CAS