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[Xavier Gonze <xavier.gonze@uclouvain.be>]

Dear Peter,

The answer to your question can be found in 

http://www.abinit.org/Infos_v5.5/input_variables/vargs.html#kptbounds

A side remark : spin-orbit is not so weak in Sb, on the order of 0.3 eV, if I remember correctly...

But ABINIT can do the computation. Use HGH pseudopotentials to get it.

Xavier

On 31 Jan 2008, at 16:28, Peter Zalden wrote:

Dear All,

trying to reproduce the calculated band structure of pure antimony published by X. Gonze in PHYSICAL REVIEW B 41 (17): 11827-11836 JUN 15 1990, I did relaxation and convergence checks first (w.r.t. ecut and ngkpt) and calculated the band structure afterwards, neglecting spin-orbital coupling (which should be weak in Sb).

Unfortunately with my choice of k-points for reproducing the band structure, I always get kinks in the bands. For calculating the points of high symmetry in the first BZ I used xcrysden, which enables you to choose points in a nice GUI. I took the article by MH Cohen in PHYSICAL REVIEW 121 (2): 387-& 1961 as a reference to find those points.

How is this calculation done usually? And which coordinates along the basis vectors of reciprocal space need to be chosen for the A7 structure to include X, K, GAM, T, W, L, (T, H)-points?

Attached to this posting you will find my input-file.

Thanks a lot in advance.

Kind Regards

Peter Zalden

 

P.S.: I used this (http://www.abinit.org/Psps/?text=../Psps/GGA_FHI/fhi) PSP for antimony.

 

-------------------- Input-file ----------------------------

prtden 1

getden2 -1

 

prteig 1

prtgeo 12

 

natom 2

ntypat 1

znucl 51

typat 1 1

acell 3*8.6205260108

angdeg 3*57.21501101

xred

3*-0.2269846

3*0.2269846

chkprim 1

 

kptopt1 1

kptopt2 -5

ngkpt 12 12 12

nshiftk 1

shiftk 0.5 0.5 0.5

 

kptbounds2

0.5 0.0 0.5 #X

0.63011 0.0 0.36989 #K?

0.0 0.0 0.0 #GAM

0.5 0.5 0.5 #T

0.76021 0.23979 0.5 #W?

0.5 0.0 0.0 #L

ndivk2 10 30 20 20 20

nband 14

nbdbuf 0

occopt 3

tsmear 0.001

 

ndtset 2

ecut 18.0

 

iscf1 7

iscf2 -2

 

nstep 100000

nline 15

toldfe1 1.0d-8

toldfe2 0.0

tolwfr2 1.0d-21

diemac 20.0

ixc 11

prtdos 1

enunit 0  

prtvol 3

timopt 2