[Wien] mbj

[Saeid Jalali]

Dear All,

 

We are performing the mbj calculations for a carbon based compound.
According to the usersguide there are three SCF cycles for mbj calculations:
first a regular calculations within LDA/GGA (we use the PBE-GGA here),
second one more cycle run_lapw -NI -i 1 , and third the mbj run after
changing the potential energy functional indxc=28 in case.in0 and index=50
in case.in0_grr.

Here we call the regular SCF cycles C1.scf, second one-more SCF cycle as
C2.scf, and the third the mbj as cycle C3.scf.

The first regular cycle and the second run_lapw -NI -i 1 are converged
smoothly. However, the third mbj cycle is stopped at lapw2 in its second
iteration.

We analyzed the problem to find the source of the error. The result is given
below, where the C2.scf line refers to the last :ITE of the second one more
SCF cycle, and the C3.scf refers to the first :ITE of the third mbj run:

 

C2.scf::NTO033: TOTAL   CHARGE IN SPHERE  1 =        3.9781366

C3.scf::NTO033: TOTAL   CHARGE IN SPHERE  1 =        2.4250427

 

C2.scf::CTO033: TOTAL   CHARGE IN SPHERE  1 =        3.9781254

C3.scf::CTO033: TOTAL   CHARGE IN SPHERE  1 =        3.9470631

 

C2.scf::DIS  :  CHARGE DISTANCE       ( 0.0000355 for atom   33 spin 1)
0.0000136

C3.scf::DIS  :  CHARGE DISTANCE       ( 1.8978668 for atom   25 spin 1)
1.5016586

 

C2.scf::NEC01: NUCLEAR AND ELECTRONIC CHARGE    366.00000   365.98257
1.00005

C3.scf::NEC01: NUCLEAR AND ELECTRONIC CHARGE    366.00000   365.98171
1.00005

 

C2.scf::FER  : F E R M I - ENERGY(TETRAH.M.)=   0.21390

C3.scf::FER  : F E R M I - ENERGY(TETRAH.M.)=  -1.44751

 

The result clearly shows that there is a jump in :NTO, :DIS, and :FER (But
in :CTO) after changing the functional to index=28.

 

In order to check whether such a jump occurs for other systems, we perform
as an example another mbj calculations for the fcc-Fe crystal. The Fe
results, which clearly show that there is not such a jump problem in Fe are
given below:

 

Fe1.scf :NTO001: TOTAL   CHARGE IN SPHERE  1 =       23.4594564

Fe2.scf :NTO001: TOTAL   CHARGE IN SPHERE  1 =       23.4235635

 

Fe1.scf :CTO001: TOTAL   CHARGE IN SPHERE  1 =       23.4594584

Fe2.scf :CTO001: TOTAL   CHARGE IN SPHERE  1 =       23.4585610

 

Fe1.scf :DIS  :  CHARGE DISTANCE       ( 0.0000025 for atom    1 spin 1)
0.0000025

Fe2.scf :DIS  :  CHARGE DISTANCE       ( 0.0397309 for atom    1 spin 1)
0.0397309

 

Fe1.scf :NEC01: NUCLEAR AND ELECTRONIC CHARGE     26.00000    25.99451
1.00021

Fe2.scf :NEC01: NUCLEAR AND ELECTRONIC CHARGE     26.00000    25.99459
1.00021

 

In order to check whether the problem comes from carbon atoms we performed
the calculation for the diamond and found that the problem cannot attributed
to the carbon atom, as the mbj diamond (just for example) is well converged.

 

We then change the mixing method to PRAT and change and reduce the mixing
parameter in case.inm to 0.01. But the problem severely exists.

Since our calculations are very heavy due to our limited computational
facility, we cannot perform many tests. So, your comments  are very valuable
for us and will be deeply appreciated. 

 

Sincerely yours,

S. Jalali

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Saeid Jalali Asadabadi,

Department of Physics, Faculty of Science,

University of Isfahan (UI), Hezar Gerib Avenue,

81744 Isfahan, Iran.

Phones:

Dep. of Phys.   :+98-0311-793 2435

Office                  :+98-0311-793 4176

Fax No.                :+98-0311-793 2409

E-mail                  :sjalali at phys.ui.ac.ir

                               :sjalali at sci.ui.ac.ir

                               :sjalali at mailaps.org

                                :saeid.jalali.asadabadi at gmail.com

                                :s_jalali_a at yahoo.com

Homepage          :http://sci.ui.ac.ir/~sjalali

www                      :http://www.ui.ac.ir

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