[Pw_forum] Relaxation with Spin-Orbit Coupling
Dal Corso Andrea
dalcorso at sissa.it
Tue Jul 13 12:23:15 CEST 2010
Difficult to say. Are you sure about the Tl PP. A ghost in particular
could cause the effects that you report.
Andrea
On Tue, 2010-07-13 at 11:59 +0200, Julen Ibanez Azpiroz wrote:
> Hello, thanks for answering,
>
> This is the input:
>
>
>
> &control
> calculation='relax',
> dt=10.D0,
> tstress=.true.
> tprnfor=.true.
> verbosity='high',
> restart_mode='from_scratch',
> prefix='si_dt_scalar',
> pseudo_dir='./',
> outdir='/lscratch/azpiroz/relax_sc_pos/'
> forc_conv_thr=1.0D-4 ,
> /
> &system
> ibrav=12,
> celldm(1)= 7.30868, celldm(2)= 1, celldm(3)= 17.044354, celldm(4)=
> 0.5,
> nat=26,
> ntyp=2,
> ecutwfc =45,
> noncolin=.true.
> lspinorb=.true.
> occupations='smearing',
> smearing='methfessel-paxton',
> degauss=0.05d0
> /
> &electrons
> conv_thr=1.0e-6,
> mixing_beta=0.3d0
> /
> &IONS
> ion_dynamics = "damp",
> pot_extrapolation = "second_order",
> wfc_extrapolation = "second_order",
> /
> ATOMIC_SPECIES
> Si 28.086 Si.rel-pbe-rrkj.UPF
> Tl 204.383 Tl.6d_relat_rrkj_nc.UPF
> ATOMIC_POSITIONS
> Tl 0.000000000 -0.000000003 -5.314678016 0 0 1
> Si -0.500000000 -0.288675141 -4.796768286 0 0 1
> Si -0.500000000 -0.288675106 -4.190720851 0 0 1
> Si 0.000000000 0.000000030 -3.983120071 0 0 1
> Si 0.000000000 0.000000005 -3.369968660 0 0 1
> Si 0.500000000 0.288675142 -3.165727013 0 0 1
> Si 0.500000000 0.288675167 -2.553252172 0 0 1
> Si -0.500000000 -0.288675100 -2.348809321 0 0 1
> Si -0.500000000 -0.288675113 -1.736391979 0 0 1
> Si 0.000000000 0.000000020 -1.531756523 0 0 1
> Si 0.000000000 0.000000029 -0.919281369 0 0 1
> Si 0.500000000 0.288675161 -0.714766469 0 0 1
> Si 0.500000000 0.288675135 -0.102266533 0 0 1
> Si -0.500000000 -0.288675135 0.102266533 0 0 1
> Si -0.500000000 -0.288675161 0.714766469 0 0 1
> Si 0.000000000 -0.000000029 0.919281369 0 0 1
> Si 0.000000000 -0.000000020 1.531756523 0 0 1
> Si 0.500000000 0.288675113 1.736391979 0 0 1
> Si 0.500000000 0.288675100 2.348809321 0 0 1
> Si -0.500000000 -0.288675167 2.553252172 0 0 1
> Si -0.500000000 -0.288675142 3.165727013 0 0 1
> Si 0.000000000 -0.000000005 3.369968660 0 0 1
> Si 0.000000000 -0.000000030 3.983120071 0 0 1
> Si 0.500000000 0.288675106 4.190720851 0 0 1
> Si 0.500000000 0.288675141 4.796768286 0 0 1
> Tl 0.000000000 0.000000003 5.314678016 0 0 1
> K_POINTS {automatic}
> 16 16 1 0 0 0
>
>
>
> This is the structure A, the output gives energy -207.10202515 Ry, but
> the forces in the ouput are:
>
>
> ! total energy = -207.10202515 Ry
> Harris-Foulkes estimate = -207.10202560 Ry
> estimated scf accuracy < 0.00000040 Ry
>
> convergence has been achieved in 19 iterations
>
> Forces acting on atoms (Ry/au):
>
>
> atom 1 type 2 force = 0.00000000 0.00000000
> -0.01317569
> atom 2 type 1 force = 0.00000000 0.00000000
> -0.00615334
> atom 3 type 1 force = 0.00000000 0.00000000
> 0.00105593
> atom 4 type 1 force = 0.00000000 -0.00000001
> -0.00059280
> atom 5 type 1 force = 0.00000000 0.00000001
> -0.00026662
> atom 6 type 1 force = 0.00000000 0.00000000
> 0.00008699
> atom 7 type 1 force = 0.00000000 0.00000000
> -0.00000917
> atom 8 type 1 force = 0.00000000 0.00000000
> -0.00002700
> atom 9 type 1 force = 0.00000000 0.00000000
> 0.00015023
> atom 10 type 1 force = 0.00000000 0.00000000
> -0.00013355
> atom 11 type 1 force = 0.00000000 0.00000000
> 0.00004536
> atom 12 type 1 force = 0.00000000 0.00000000
> -0.00005356
> atom 13 type 1 force = 0.00000000 0.00000000
> 0.00008346
> atom 14 type 1 force = 0.00000000 0.00000000
> -0.00008346
> atom 15 type 1 force = 0.00000000 0.00000000
> 0.00005356
> atom 16 type 1 force = 0.00000000 0.00000000
> -0.00004536
> atom 17 type 1 force = 0.00000000 0.00000000
> 0.00013355
> atom 18 type 1 force = 0.00000000 0.00000000
> -0.00015023
> atom 19 type 1 force = 0.00000000 0.00000000
> 0.00002700
> atom 20 type 1 force = 0.00000000 0.00000000
> 0.00000917
> atom 21 type 1 force = 0.00000000 0.00000000
> -0.00008699
> atom 22 type 1 force = 0.00000000 -0.00000001
> 0.00026662
> atom 23 type 1 force = 0.00000000 0.00000001
> 0.00059280
> atom 24 type 1 force = 0.00000000 0.00000000
> -0.00105593
> atom 25 type 1 force = 0.00000000 0.00000000
> 0.00615334
> atom 26 type 2 force = 0.00000000 0.00000000
> 0.01317569
>
> as I said in the previous email, when SOC was not included the forces
> were <1.0D-4Ry/au.
>
> After many cycles it relaxes to structure B:
>
>
> 1 Tl tau( 1) = ( 0.0000000 -0.0000002
> -5.4750706 )
> 2 Si tau( 2) = ( -0.5000000 -0.2886754
> -4.9286617 )
> 3 Si tau( 3) = ( -0.5000000 -0.2886751
> -4.3089294 )
> 4 Si tau( 4) = ( 0.0000000 0.0000001
> -4.0900306 )
> 5 Si tau( 5) = ( 0.0000000 0.0000005
> -3.4646493 )
> 6 Si tau( 6) = ( 0.5000000 0.2886757
> -3.2486536 )
> 7 Si tau( 7) = ( 0.5000000 0.2886753
> -2.6244846 )
> 8 Si tau( 8) = ( -0.5000000 -0.2886750
> -2.4089562 )
> 9 Si tau( 9) = ( -0.5000000 -0.2886748
> -1.7850326 )
> 10 Si tau( 10) = ( 0.0000000 0.0000002
> -1.5698553 )
> 11 Si tau( 11) = ( 0.0000000 0.0000013
> -0.9460530 )
> 12 Si tau( 12) = ( 0.5000000 0.2886761
> -0.7311323 )
> 13 Si tau( 13) = ( 0.5000000 0.2886753
> -0.1074118 )
> 14 Si tau( 14) = ( -0.5000000 -0.2886753
> 0.1074118 )
> 15 Si tau( 15) = ( -0.5000000 -0.2886761
> 0.7311323 )
> 16 Si tau( 16) = ( 0.0000000 -0.0000013
> 0.9460530 )
> 17 Si tau( 17) = ( 0.0000000 -0.0000002
> 1.5698553 )
> 18 Si tau( 18) = ( 0.5000000 0.2886748
> 1.7850326 )
> 19 Si tau( 19) = ( 0.5000000 0.2886750
> 2.4089562 )
> 20 Si tau( 20) = ( -0.5000000 -0.2886753
> 2.6244846 )
> 21 Si tau( 21) = ( -0.5000000 -0.2886757
> 3.2486536 )
> 22 Si tau( 22) = ( 0.0000000 -0.0000005
> 3.4646493 )
> 23 Si tau( 23) = ( 0.0000000 -0.0000001
> 4.0900306 )
> 24 Si tau( 24) = ( 0.5000000 0.2886751
> 4.3089294 )
> 25 Si tau( 25) = ( 0.5000000 0.2886754
> 4.9286617 )
> 26 Tl tau( 26) = ( 0.0000000 0.0000002
> 5.4750706 )
>
>
>
>
> were the output says:
>
>
> ! total energy = -207.08193686 Ry
> Harris-Foulkes estimate = -207.08193687 Ry
> estimated scf accuracy < 0.00000002 Ry
>
> convergence has been achieved in 19 iterations
>
> Forces acting on atoms (Ry/au):
>
> atom 1 type 2 force = 0.00000000 -0.00000001
> -0.00021452
> atom 2 type 1 force = 0.00000000 0.00000004
> -0.00028392
> atom 3 type 1 force = 0.00000000 0.00000004
> -0.00036455
> atom 4 type 1 force = 0.00000000 -0.00000001
> -0.00029396
> atom 5 type 1 force = 0.00000000 -0.00000002
> -0.00029563
> atom 6 type 1 force = 0.00000000 -0.00000008
> -0.00028951
> atom 7 type 1 force = 0.00000000 0.00000003
> -0.00018682
> atom 8 type 1 force = 0.00000000 0.00000006
> -0.00026107
> atom 9 type 1 force = 0.00000000 -0.00000026
> -0.00008411
> atom 10 type 1 force = 0.00000000 0.00000037
> -0.00018718
> atom 11 type 1 force = 0.00000000 -0.00000073
> -0.00001065
> atom 12 type 1 force = 0.00000000 0.00000047
> -0.00011851
> atom 13 type 1 force = 0.00000000 -0.00000049
> 0.00004827
> atom 14 type 1 force = 0.00000000 0.00000049
> -0.00004827
> atom 15 type 1 force = 0.00000000 -0.00000047
> 0.00011851
> atom 16 type 1 force = 0.00000000 0.00000073
> 0.00001065
> atom 17 type 1 force = 0.00000000 -0.00000037
> 0.00018718
> atom 18 type 1 force = 0.00000000 0.00000026
> 0.00008411
> atom 19 type 1 force = 0.00000000 -0.00000006
> 0.00026107
> atom 20 type 1 force = 0.00000000 -0.00000003
> 0.00018682
> atom 21 type 1 force = 0.00000000 0.00000008
> 0.00028951
> atom 22 type 1 force = 0.00000000 0.00000002
> 0.00029563
> atom 23 type 1 force = 0.00000000 0.00000001
> 0.00029396
> atom 24 type 1 force = 0.00000000 -0.00000004
> 0.00036455
> atom 25 type 1 force = 0.00000000 -0.00000004
> 0.00028392
> atom 26 type 2 force = 0.00000000 0.00000001
> 0.00021452
>
>
> This is not forces <1.0D-4Ry/au, but its the most I could converge.
> The energy is higher than in the first case. I do not know if it has
> something to do with the problem, but the fully relativistic
> pseudopotentials were checked in simpler systems giving good results.
> Thank you in advance
>
> Julen
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--
Andrea Dal Corso Tel. 0039-040-3787428
SISSA, Via Beirut 2/4 Fax. 0039-040-3787528
34151 Trieste (Italy) e-mail: dalcorso at sissa.it
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