[Pw_forum] Regarding error during adsorption of bromine in graphene

[Lorenzo Paulatto]

WHen using ultrasoft pseudopotentials (as you do), this error may 
indicate that the atoms got much closer to each other than they should. 
You can try to check the last relaxed positions with xcrysden or, put 
them back in an input file and use dist.x, to verify that nothing is 
suspect.

hth

On 03/07/17 06:05, nipesh dulal wrote:
> Dear QE experts
> 
> i am doing adsorption of bromine in 3*3 graphene sheet. But there comes 
> an error after one scf cycle which is mentioned below,
> 
> 
> 
> Writing output data file bromine_relax_pb.save
>       NEW-OLD atomic charge density approx. for the potential
> 
>       negative rho (up, down):  1.894E-04 0.000E+00
> 
>       total cpu time spent up to now is     3015.2 secs
> 
>       per-process dynamical memory:   765.2 Mb
> 
>       Self-consistent Calculation
> 
>       iteration #  1     ecut=    45.00 Ry     beta=0.60
>       Davidson diagonalization with overlap
> 
> 
>       Error in routine cdiaghg (332):
>       S matrix not positive definite
> 
> 
>       stopping ...
> 
> Here is the input file i have used
> 
> &control
> calculation='relax'
> restart_mode='from_scratch'
> prefix='bromine_relax_pb'
> outdir='/home/physics/Downloads/graphene/bromine',
> pseudo_dir = '/home/physics/Downloads/graphene/pseudopotentials',
> tstress=.true.
> tprnfor=.true.
> verbosity='high'
> forc_conv_thr=1.0d-3
> etot_conv_thr=1.0d-4
> /
> &SYSTEM
> ibrav=4
> celldm(1)=13.95
> celldm(3)=2.71
> nat=20
> ntyp=2
> ecutwfc=45.0
> ecutrho=450
> occupations='smearing'
> smearing='mv'
> degauss=0.002
> vdw_corr='dft-d'
> /
> &ELECTRONS
> diagonalization='david'
> mixing_mode='plain'
> electron_maxstep = 100
> mixing_beta=0.6
> conv_thr = 1.0D-8
> /
> &IONS
> ion_dynamics='bfgs'
> /
> 
> ATOMIC_SPECIES
> C 12.011 C.pbe-rrkjus.UPF
> Br 79.90 Br.pbe-n-rrkjus_psl.0.2.UPF
> ATOMIC_POSITIONS (angstrom)
> C  0.001428319  -0.002221684   0.000000000
> C  1.231420386   0.708643125   0.000000000
> C  2.462100004  -0.002217662   0.000000000
> C  3.692093444   0.708644819   0.000000000
> C  -1.228907612  2.128792409   0.000000000
> C  0.001083491   2.839646136   0.000000000
> C  1.231766190   2.128786536   0.000000000
> C  2.461756350   2.839644042   0.000000000
> C  4.922778865  -0.002223457   0.000000000
> C  6.152768802   0.708640258   0.000000000
> C  3.692440675   2.128788864   0.000000000
> C  4.922431282   2.839647087   0.000000000
> C  -2.459244768  4.259790447   0.000000000
> C  -1.229251320  4.970648411   0.000000000
> C  0.001427750   4.259792429   0.000000000
> C  1.231421212   4.970653053   0.000000000
> C  2.462102410   4.259795383   0.000000000
> C  3.692093014   4.970654542   0.000000000
> Br 2.461756350   2.558726619   3.500000000
> Br 2.461756350   0.278726619   3.500000000
> 
> K_POINTS {automatic}
> 5 5 1 0 0 0
> 
> 
> With Best Regards
> Nipesh Dulal
> Tribhuwan University
> Kathmandu , Nepal
> 
> 
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-- 
Dr. Lorenzo Paulatto
IdR @ IMPMC -- CNRS & Université Paris 6
phone: +33 (0)1 442 79822 / skype: paulatz
www:   http://www-int.impmc.upmc.fr/~paulatto/
mail:  23-24/423 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05