[Pw_forum] ultrasoft Cs pseudopotential

[Miguel Martínez]

Dear all,

Personally, I found the PBE Cs pseudo available in the library suitable
for metallic bcc Cs. However, and probably due to charge transfer, I
found it unsuitable at higher pressures (beyond 2 GPa). I know that 1
electron sodium PPs are not really trustworthy in the fcc phase beyond
60 GPa (although results are not too far off). Alkalis plus very high
pressure has always meant extra electrons for me.

Having been asked (and just noticed), here's my 9-electron PBE pseudo.
I'm sure the ld1 masters will have suggestions to it, and they are more
than welcome (especially since I hate generating pseudopotentials with
semicore electrons).

You'll have to mkdir Cs9 before running ld1.x. However, you can use the
nice plot_dlog (located in espresso-4.2/atomic_doc/paw_library) script
to see the logarithmic derivatives. In any case, all the usual warnings
apply: "test first" and "use at your own risk". 

 &input
    title='Cs',
    prefix='Cs9/ld1',
    zed=55.0,
    rel=1,
     rlderiv=3.01,
     eminld=-5.0,
     emaxld=3.0,
     deld=0.02d0,
     nld=3,
    config='[Kr] 4d10 5s2 5p6 6s1 5d0 6p0'
    iswitch=3,
    dft='PBE',
 /
 &inputp
   lloc=-1,
   rcloc=2.6
   nlcc=.true.
   rcore=1.3
   rho0=0.0
   tm=.true.
   pseudotype=3,
     which_augfun='AE',
     new_core_ps=.true.,
   file_pseudopw='Cs.pbe-nsp-van.UPF',
   author='MMC',
 /
7
5S  1  0  2.00  0.00  1.40  2.60
6S  2  0  1.00  0.00  1.40  2.60
6S  3  0 -1.00  0.50  1.40  2.60
5P  2  1  6.00  0.00  1.60  2.00
5P  3  1  0.00 -0.05  1.60  2.00
5D  3  2  0.00  0.00  1.80  2.20
5D  4  2  0.00  0.50  1.80  2.20



Regards,

Miguel

PS: You may want to put a slight charge in the p channel. That will
mean more tests, though.

On Thu, 01 Jul 2010 16:28:47 +0100 Nicola Marzari <marzari at MIT.EDU>
wrote:
> Suza W wrote:
> >
> >
> >  Dear Nicola,
> >  
> >  Thanks a lot for your reply. The pseudo mentioned by you has one 
> > electron in valence. However,  
> >  from PW-FORUM, I came to know that it might be better to use 9 
> > valence electrons in case of Cesium (Cs).
> >  May I get a Cs Ultra-soft  PP (LDA & GGA), preferably with 9 
> > electrons in valence, from your USPP collection?
> >  
> >  Yours sincerely,
> >  Suza
> 
> 
> Dear Suza,
> 
> the few psuedos we generated are all public, and I do not have a Cs
> with 9 electrons -
> neither norm-conserving nor USPP.
> 
> The one on the database has non-linear core corrections, so it should
> be quite good.
> Other option for you is to learn on how to generate pseudos - there is
> a tutorial by Andrea Dal Corso on the quantum=espresso page (Santa
> Barbara school).
> 
>              nicola
> 
> 



-- 
----------------------------------------
Dr. Miguel Martinez Canales
   Department of Physics & Astronomy
   University College London
   Gower Street, London, WC1E 6BT (UK)
Fax:  +44 207 679 0595
Tlf:  +44 207 678 3476
----------------------------------------

 "If you have an apple and I have an apple and
 we exchange these apples then you and I will
 still each have one apple. But if you have an
 idea and I have an idea and we exchange these
 ideas, then each of us will have two ideas."

 George Bernard Shaw