[Wien] Once again about Ni non-magnetic bcc calculation

[Lyudmila Dobysheva]

By the way to the WIEN mailing list admin: I couldn't load the October archiv 
with the first discussion on this theme, only few letters are there. 

In a letter of 24 Nov. 2004 12:07 Dominik Legut wrote:

> Once again about Ni non-magnetic bcc calculation
> On October 26, we wrote about the discontinuity of calculated total energy
> as a function of volume for the bcc structure of non-magnetic Ni within the
> GGA.
...
> The results are as follows (Vexp corresponds to the fcc lattice constant of
> 6.651835 a.u. for fcc):

Was it, in fact, bcc or fcc? It doesn't matter, of course, but I see that if 
it is fcc, with the constant given you had to change the Rmt somewhere in 
your V-E curve, I assume that you did it in that place of discontinuity, (?).
If so: I thought that such jumps are not surprising, you cannot make the basis 
for the new MT structure entirely equivalent to the old one.

> We performed tests where we changed the Gmax parameter to 14,16,18,24 and
> 30. However we have not succeeded to suppress the discontinuity by
> increasing the Gmax, as proposed by A. Postnikov in his letter:
> The position of discontinuity in the total energy occurs at certain volume
> that depends  on the values of RMT and RKmax parameters, nevertheless the
> value of Gmax and number of KPoints do not affect the position of
> discontinuity.

And what about the magnitude? Was it equal for all cases? Did you reach the 
convergency of this jump with increasing the parameter Gmax and others?

Best regards,
  Lyudmila Dobysheva 
------------------------------------------------------------------
Phys.-Techn. Institute of       | Tel.(home):   7 (3412) 442118
Ural Br. of Russian Ac. of Sci. | Tel.(office): 7 (3412) 218988
426001 Izhevsk, ul.Kirova 132   | Fax:          7 (3412) 250614
RUSSIA                          | E-mail: lyu at otf.fti.udmurtia.su
------------------------------------------------------------------
http://fti.udm.ru/ltt/personals/dobysh.htm
------------------------------------------------------------------