Dear sir,
I have done calculations according your suggestions.
I got cohesive energy at 0 K is as follows.
934.7 kJ/mol
749.6 kJ/mol (with dispersion correction)
731.7 kJ/mol (with 2x2x1 k-point)
670.0 kJ/mol (Experiment at 0 K)
I increased plane wave cutoff to 35 to 40 Ryd., there is no change in the
values.
I got surface energy as follows.
11.7 kJ/mol/Angstrom^2
28.4 kJ/mol/Angstrom^2 (with dispersion correction)
28.4 kJ/mol/Angstrom^2 (with 2x2x1 k-point)
14.9 kJ/mol/Angstrom^2 (Experiment at 0 K)
How to refine my results in such way that i will get close to experimental
results by tuning input parameters. Please suggest and your information is
valuable to me.
In single Iridium case, the input file contains additional nspin=2 and
starting_magnetization(1)=1 parameters and I didn't include those
parameters in the bulk Iridium case.
I am attaching one input file with dispersion correction as shown below.
************************************************************************
Structure: Ir fcc(111) ; (3x2x2) SUPER-CELL
------------------------------------------------------------------------
------------------------------------------------------------------------
6 Layers slab
************************************************************************
&control
calculation='relax',
prefix='ir_ch',
nstep=5000,
etot_conv_thr=1.0D-5,
forc_conv_thr=1.0D-4,
pseudo_dir = '/home/venkat/ORR1/PPS1'
/
&system
ibrav=0,
nat=72,
ntyp=1,
ecutwfc = 35.D0,
ecutrho=350.D0,
nosym=.true.,
occupations='smearing',
smearing='m-p',
degauss=0.07D0,
vdw_corr='grimme-d2'
/
&electrons
electron_maxstep=2000,
diagonalization='david',
mixing_beta = 0.7D0,
conv_thr = 1.0D-8,
scf_must_converge=.true.
mixing_mode = 'local-TF' ,
startingpot = 'atomic' ,
startingwfc = 'atomic' ,
/
&ions
ion_dynamics='bfgs'
/
ATOMIC_SPECIES
Ir 192.217 Ir.pw91-n-rrkjus_psl.0.2.3.UPF
CELL_PARAMETERS angstrom
8.1437488 0.00000000 0.00000000
0.0000000 9.40359112 0.00000000
0.0000000 0.00000000 13.29868610
ATOMIC_POSITIONS angstrom
Ir 6.78645733 5.48542817 6.64934305
Ir 5.42916587 7.83632593 6.64934305
Ir 5.42916587 4.70179556 4.43289536
Ir 6.78645733 7.05269336 4.43289536
Ir 5.42916587 6.26906075 2.21644768
Ir 6.78645733 8.61995854 2.21644768
Ir 4.07187440 5.48542817 6.64934305
Ir 2.71458293 7.83632593 6.64934305
Ir 2.71458293 4.70179556 4.43289536
Ir 4.07187440 7.05269336 4.43289536
Ir 2.71458293 6.26906075 2.21644768
Ir 4.07187440 8.61995854 2.21644768
Ir 1.35729146 5.48542817 6.64934305
Ir 0.00000000 7.83632593 6.64934305
Ir 0.00000000 4.70179556 4.43289536
Ir 1.35729146 7.05269336 4.43289536
Ir 0.00000000 6.26906075 2.21644768
Ir 1.35729146 8.61995854 2.21644768
Ir 6.78645733 0.78363261 6.64934305
Ir 5.42916587 3.13453037 6.64934305
Ir 5.42916587 0.00000000 4.43289536
Ir 6.78645733 2.35089780 4.43289536
Ir 5.42916587 1.56726519 2.21644768
Ir 6.78645733 3.91816298 2.21644768
Ir 4.07187440 0.78363261 6.64934305
Ir 2.71458293 3.13453037 6.64934305
Ir 2.71458293 0.00000000 4.43289536
Ir 4.07187440 2.35089780 4.43289536
Ir 2.71458293 1.56726519 2.21644768
Ir 4.07187440 3.91816298 2.21644768
Ir 1.35729146 0.78363261 6.64934305
Ir 0.00000000 3.13453037 6.64934305
Ir 0.00000000 0.00000000 4.43289536
Ir 1.35729146 2.35089780 4.43289536
Ir 0.00000000 1.56726519 2.21644768
Ir 1.35729146 3.91816298 2.21644768
Ir 6.78645733 5.48542817 0.00000000
Ir 5.42916587 7.83632593 0.00000000
Ir 5.42916587 4.70179556 -2.21644769
Ir 6.78645733 7.05269336 -2.21644769
Ir 5.42916587 6.26906075 -4.43289537
Ir 6.78645733 8.61995854 -4.43289537
Ir 4.07187440 5.48542817 0.00000000
Ir 2.71458293 7.83632593 0.00000000
Ir 2.71458293 4.70179556 -2.21644769
Ir 4.07187440 7.05269336 -2.21644769
Ir 2.71458293 6.26906075 -4.43289537
Ir 4.07187440 8.61995854 -4.43289537
Ir 1.35729146 5.48542817 0.00000000
Ir 0.00000000 7.83632593 0.00000000
Ir 0.00000000 4.70179556 -2.21644769
Ir 1.35729146 7.05269336 -2.21644769
Ir 0.00000000 6.26906075 -4.43289537
Ir 1.35729146 8.61995854 -4.43289537
Ir 6.78645733 0.78363261 0.00000000
Ir 5.42916587 3.13453037 0.00000000
Ir 5.42916587 0.00000000 -2.21644769
Ir 6.78645733 2.35089780 -2.21644769
Ir 5.42916587 1.56726519 -4.43289537
Ir 6.78645733 3.91816298 -4.43289537
Ir 4.07187440 0.78363261 0.00000000
Ir 2.71458293 3.13453037 0.00000000
Ir 2.71458293 0.00000000 -2.21644769
Ir 4.07187440 2.35089780 -2.21644769
Ir 2.71458293 1.56726519 -4.43289537
Ir 4.07187440 3.91816298 -4.43289537
Ir 1.35729146 0.78363261 0.00000000
Ir 0.00000000 3.13453037 0.00000000
Ir 0.00000000 0.00000000 -2.21644769
Ir 1.35729146 2.35089780 -2.21644769
Ir 0.00000000 1.56726519 -4.43289537
Ir 1.35729146 3.91816298 -4.43289537
K_POINTS gamma
Venkataramana
PhD student
IIT Bombay
Mumbai
On Mon, Oct 5, 2015 at 9:20 AM, Venkataramana Imandi <
venkataramana.ima...@gmail.com> wrote:
> Dear prof. Stefano,
> Thank you very much for kind your help.
> I will check results.
>
> On Sat, Oct 3, 2015 at 2:59 PM, Venkataramana Imandi <
> venkataramana.ima...@gmail.com> wrote:
>
>> Dear prof. *STEFANO DE GIRONCOLI*
>>
>> Many thanks for spontaneous reply. On the basis of your answer, If I
>> understood correctly, I can use nspin=2 for atomic Iridium and bulk Iridium
>> (since Iridium is paramagnetic from literature data). However, I have to
>> specify starting_magnetization in the input file in the both atomic Iridium
>> and bulk Iridium
>> input files. The keywords list information says that values range between
>> -1 (all spins down for the valence electrons of atom type 'i') to 1 (all
>> spins up). Iridium has three unpaired electrons in the spin up.
>> 1. It indicates can I use starting_magnetization(1)=1 along with nspin=2.
>> 2. If not that value, what value I have to use, I don't know, please
>> suggest me.
>> 3. I am not using full relativistic pseudopotential for Iridium, so, I
>> can skip nspin=4, am I correct ?.
>>
>> Please verify my assumptions.
>> The reply of previous thread of clean stop of running job, now I got
>> clean stop during running job.
>>
>>
>> On Sat, Oct 3, 2015 at 12:52 PM, Venkataramana Imandi <
>> venkataramana.ima...@gmail.com> wrote:
>>
>>>
>>> Dear all
>>>
>>> I want to calculate ground state total energy of single Iridium neutral
>>> gaseous atom.
>>> The electronic configuration of Iridium atom is [Xe].4f^14.5d^7.6s^2 and
>>> in the 5d orbital, three unpaired electrons are there.
>>> So, the resultant spin multiplicity is 4. Hence, in keywords list,
>>> nspin=4 or noncolin=.true. is essential.
>>> I am asking that whether nspin means spin multiplicity or not ?.
>>> Am i correct for determining total energy of Iridium with nspin=4 or
>>> noncolin=.true. ?
>>> In case of bulk Iridium (total atoms=72), then can I skip nspin=4 or
>>> noncolin=.true. ?
>>> In case of bulk Iridium electrons can get paired or not ?
>>>
>>> Finally I want to calculate cohesive energy of bulk Iridium.
>>>
>>> I am extremely say sorry, if questions are fundamental and trivial.
>>>
>>> Any suggestions are appreciated and thanks in anticipated.
>>>
>>>
>>> venkataramana
>>> PhD student
>>> IIT Bombay
>>> Mumbai
>>>
>>
>>
>>
>> --
>> venkataramana
>>
>
>
>
> --
> venkataramana
>
--
venkataramana
_______________________________________________
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum
