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[Emmanuel Arras <emmanuel.arras@cea.fr>]

Indeed, but it is the same with spin polarized (colinear) calculations. If you double the number of bands, it means your electronic state can be "full up", with no electron at all in the down states. It is usualy not the case, especially if you don't have only magnetic atoms.


Anglade Pierre-Matthieu a écrit :

c65e87810807160004k3b290074ka974d07f4e17ad5a@mail.gmail.com" type="cite">

Within Abinit, for non spin-polarised calculation the bands can be
occupied by two electrons. Then you need twice less electrons for such
computations.

PMA

On Tue, Jul 15, 2008 at 7:37 PM, Emmanuel Arras <emmanuel.arras@cea.fr> wrote:
  

I think nband is the same, whether you are spin polarized or not.


Aldo Humberto Romero a écrit :

It is clear from you input that you have use A SINGLE NBAND
and the number of bands should be at least

sum_i  (number_of_valence_electrons)*number_atoms_of_type_i_unit_cell

half of this number if it is a spin polarized and
at least this number it is spin polarized

regards

-aldo.

PS are you sure you want to do calculations for a single K point?




Dear Abinit users,

I am doing calculation on GaAs, Actually I try to repeat everything I
learn
from abinit tutorial 1-4. But I have problem when I try to get the
interatomic
distance. I got these lines in log file

------------------------------------------------------------------------------------------------------------------------------
inkpts : istwfk preprocessed, gives following first values (max. 6): 2

 chkneu : ERROR -
  Initialization of occ, with occopt=	1
  There are not enough bands to get charge balance right
 Action : modify input file ...
  (check the pseudopotential charges, the variable charge,
  and the declared number of bands, nband)

 leave_new : decision taken to exit ...

----------------------------------------------------------------------------------------------------------------------------------

My input file is
--------------------------------------------------------------------------------------------------------------------------------

ionmov	4
ntime	10
tolmxf	5.0d-4
xcart
   0.0	0.0  0.0
   0.50 0.0  0.50
   0.0	0.50 0.50
   0.50 0.50 0.0
   0.25 0.25 0.25
   0.75 0.75 0.25
   0.75 0.25 0.75
   0.25 0.75 0.75
toldff	5.0d-5
nband	 1
acell 10.64388 10.64388 10.64388


#Definition of the atom types

ntypat 2	  # There is one type of atom
znucl 31 33


#Definition of the atoms

natom 8 		      # There are eights atoms
typat  1 1 1 1 2 2 2 2


#Definition of the planewave basis set

ecut 10.0


#Definition of the k-point grid

nkpt 1


#Definition of the SCF procedure

nstep 20
diemac 2.0
----------------------------------------------------------------------------------------------------------------------------

Please tell me how too solve my problem. Thank you in advance for the help



---------------------------------------------------
Prof. Aldo Humberto Romero
CINVESTAV-Unidad Queretaro
Libramiento Norponiente 2000
CP 76230, Queretaro, QRO, Mexico
tel: 442 211 9909
fax: 442 211 9938
email: aromero@qro.cinvestav.mx
       aldorome@gmail.com
www: qro.cinvestav.mx/~aromero