[Pw_forum] pseudopotential for Uranium

[Sharat Chandra]

Hi

I am trying to generate a pseudopotential for Uranium for use in my calculations for UFe2 compound. I have tried converting the fhi PPs available from the ABINIT web site, as well as generating the TM PP based on the publication by Crocombette etal, Phys. Rev. B, 64, 104107, 2001, and also trying to generate the ultrasoft PP, using the atom code. I have checked the mailing list and did not find any discussion with emphasis on this topic.

The fhi PPs have 6 electrons, while the PPs generated using the PRB data have 12 electrons.

I have not been able to get the proper lattice parameter and bulk modulus of U in fcc phase, published in the same paper, which are 134.3 a.u.^3 and 154 GPa. I either get too large values, or too small values, based on the number of electrons in the PPs.

Can some one please tell me what I am doing wrong? If any one can tell me what are the proper values for rcore and rcloc, I will be very grateful. I have put below the different inputs that I have used to generate the PPs.

-------------- SR, Ultrasoft, 6 electrons ---------------------------------
 &input
        title='U',
        zed=92.0,
        rel=1,
        iswitch=3,
        rlderiv=2.50,
        eminld=-4.0,
        emaxld=4.0,
        deld=0.02,
        nld=5,
        config='[Rn] 5f3 6d1 7s2',
        dft='PBE'
 /
 &inputp
        pseudotype=3,
        lloc=0,
        file_pseudopw='Urel.SR.PBE.UPF',
        nlcc=.true.,
        rcore=1.5,
        rcloc=2.5,
 /
3
5F  4  3  3.00  0.00  2.90  2.90  3.50
6D  3  2  1.00  0.00  3.50  3.50  2.50
7S  1  0  2.00  0.00  2.80  2.80  0.00
-------------------------------------------------------------------------

---------------- SR, TM, 12 electrons, PRB inputs ---------------------
 &input
        title='U',
        zed=92.0,
        rel=1,
        iswitch=3,
        rlderiv=2.50,
        eminld=-4.0,
        emaxld=4.0,
        deld=0.02,
        nld=5,
        dft='PBE'
 /
5
6S  6  0  2.00  0.50
6P  6  1  6.00  1.50
6D  6  2  1.00  2.50
5F  5  3  3.00  3.50
7S  7  0  2.00  0.50
 &inputp
        pseudotype=2,
        lloc=-1,
        file_pseudopw='Urel.SR.PBE.TM2.UPF',
        nlcc=.true.,
        tm=.true.,
        rcore=1.2,
        rcloc=1.9,
 /
4
5F  4  3  3.00  0.00  1.26  1.26
6P  2  1  6.00  0.00  1.52  1.52
6D  3  2  1.00  0.00  2.20  2.20
6S  1  0  2.00  0.00  1.26  1.26
--------------------------------------------------------------------

Regards and thanks for your time.

Dr. Sharat Chandra

Materials Science Division

Indira Gandhi Centre for Atomic Research

Kalpakkam 603 102, TN, India



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