[Pw_forum] a question about MnSe (was Pw_forum Digest, Vol 43, Issue 37)
Stefano de Gironcoli
degironc at sissa.it
Fri Jan 21 10:12:08 CET 2011
Dear Bongani Ngwenya,
Please DO NOT reply to a Digest message .. this messes up thread search.
If one is interested in a AFM solution it is correct to define 2 Mn
species (Mn1 and Mn2) in the ATOMIC_SPECIES card and use the two labels
in ATOMIC_POSITIONS to distinguish the two types.
stefano
On 01/21/2011 10:04 AM, Bongani Ngwenya wrote:
> I can see that you need to put Mn once in your ATOMIC SPECIES and use Mn
> twice to indicate ATOMIC POSITIONS than using Mn1 and Mn2.
>
> On Fri, Jan 21, 2011 at 10:34 AM,<pw_forum-request at pwscf.org> wrote:
>
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>> Today's Topics:
>>
>> 1. Re: a question about MnSe (jia chen)
>> 2. Re: a question about MnSe (Lorenzo Paulatto)
>> 3. Re: a question about MnSe (mohnish pandey)
>> 4. Re: a question about MnSe (Prasenjit Ghosh)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Thu, 20 Jan 2011 13:37:16 -0500
>> From: jia chen<jiachen at princeton.edu>
>> Subject: Re: [Pw_forum] a question about MnSe
>> To: PWSCF Forum<pw_forum at pwscf.org>
>> Message-ID:
>> <AANLkTinL+iV_PozddAO0KjEx1CqTALsDnYqLFU0MoLg1 at mail.gmail.com<AANLkTinL%2BiV_PozddAO0KjEx1CqTALsDnYqLFU0MoLg1 at mail.gmail.com>
>> Content-Type: text/plain; charset="iso-8859-1"
>>
>> Dear All,
>>
>> I also have a question about vc-relax. How do you know if your cutoff is
>> large enough to overcome Pulay stress, or you can do something else to get
>> rid of it in you calculations. Thanks.
>>
>> Best Wishes
>> jia
>>
>> On Wed, Jan 19, 2011 at 11:57 AM, mohnish pandey<mohnish.iitk at gmail.com
>>> wrote:
>>> Dear QE users,
>>> I am trying to do bulk calculations for MnSe
>> in
>>> rocksalt and wurtzite structure. Its has AFM ground state in rocksalt
>>> structure but after checking convergence I am finding "rocksalt"
>> structure
>>> to be energetically higher than wurtzite structure. I am pasting my
>> segments
>>> of input and output files. Can anybody please help me in figuring out the
>>> problem.
>>>
>>> *INPUT FOR ROCKSALT*
>>>
>>> &control
>>> calculation = 'vc-relax'
>>> restart_mode='restart',
>>> wf_collect = .true.
>>> prefix='mnse',
>>> pseudo_dir = '/home/mohnish/mnse-rocksalt-bulk',
>>> outdir='/home/mohnish/mnse-rocksalt-bulk',
>>> tprnfor = .true.,
>>> tstress=.true.
>>> /
>>> &system
>>> ibrav= 0, celldm(1)= 10.3026, nat= 4, ntyp= 3,
>>> ecutwfc = 40.0, ecutrho = 320.0,
>>> occupations='smearing', smearing='gauss', degauss=0.01,
>>> nspin=2,
>>> starting_magnetization(1)= 0.0,
>>> starting_magnetization(2)= 0.5,
>>> starting_magnetization(3)=-0.5,
>>> /
>>> &electrons
>>> diagonalization='david'
>>> mixing_mode = 'plain'
>>> mixing_beta = 0.4
>>> conv_thr = 1.0d-8
>>> startingpot = 'file'
>>> startingwfc = 'file'
>>> /
>>> &IONS
>>> ion_dynamics='bfgs'
>>> trust_radius_max = 0.40
>>> trust_radius_ini = 0.20
>>> /
>>> &CELL
>>> cell_dynamics='bfgs',
>>> /
>>> ATOMIC_SPECIES
>>> Se 78.960 Se.pbe-van.UPF
>>> Mn1 54.938 Mn.pbe-sp-van_mit.UPF
>>> Mn2 54.938 Mn.pbe-sp-van_mit.UPF
>>> CELL_PARAMETERS
>>> 0.50 0.50 1.00
>>> 0.50 1.00 0.50
>>> 1.00 0.50 0.50
>>> ATOMIC_POSITIONS {crystal}
>>> Se 0.25 0.25 0.25
>>> Se 0.75 0.75 0.75
>>> Mn1 0.0 0.0 0.0
>>> Mn2 0.5 0.5 0.5
>>> K_POINTS {automatic}
>>> 6 6 6 0 0 0
>>>
>>> *OUTPUT FOR ROCKSALT*
>>>
>>> bfgs converged in 8 scf cycles and 4 bfgs steps
>>> (criteria: energy< 0.10E-03, force< 0.10E-02, cell< 0.50E+00)
>>>
>>> End of BFGS Geometry Optimization
>>>
>>> Final enthalpy = -464.4688263706 Ry
>>> Begin final coordinates
>>> new unit-cell volume = 533.55466 a.u.^3 ( 79.06464 Ang^3 )
>>>
>>> CELL_PARAMETERS (alat= 10.30260000)
>>> 0.494008772 0.494008772 0.990589056
>>> 0.494008772 0.990589056 0.494008772
>>> 0.990589056 0.494008772 0.494008772
>>>
>>> ATOMIC_POSITIONS (crystal)
>>> Se 0.249999854 0.249999854 0.249999854
>>> Se 0.750000146 0.750000146 0.750000146
>>> Mn1 0.000000000 0.000000000 0.000000000
>>> Mn2 0.500000000 0.500000000 0.500000000
>>> End final coordinates
>>>
>>> *INPUT FOR WURTZITE*
>>>
>>> &control
>>> calculation = 'vc-relax',
>>> restart_mode='restart',
>>> verbosity = 'high'
>>> wf_collect = .true.
>>> outdir='/home/mohnish/mnse-wurtzite-bulk',
>>> pseudo_dir='/home/mohnish/mnse-wurtzite-bulk'
>>> prefix='mnse',
>>> tstress = .true.,
>>> tprnfor = .true.,
>>> /
>>> &system
>>> ibrav= 4, a = 4.178, c = 6.783,nat= 4, ntyp= 3,
>>> ecutwfc =
>>> 40,ecutrho=320,occupations='smearing',degauss=0.01,smearing='gaussian',
>>> nspin =2,starting_magnetization(1)=0.5,starting_magnetization(2)=
>>> -0.5,
>>> /
>>> &electrons
>>> diagonalization='david'
>>> mixing_mode = 'plain'
>>> mixing_beta = 0.4
>>> conv_thr = 1.0d-8
>>> startingpot = 'file'
>>> startingwfc = 'file'
>>> /
>>> &IONS
>>> ion_dynamics='bfgs'
>>> trust_radius_max = 0.40
>>> trust_radius_ini = 0.20
>>> /
>>> &CELL
>>> cell_dynamics='bfgs',
>>> /
>>> ATOMIC_SPECIES
>>> Mn1 54.938 Mn.pbe-sp-van_mit.UPF
>>> Mn2 54.938 Mn.pbe-sp-van_mit.UPF
>>> Se 78.960 Se.pbe-van.UPF
>>> ATOMIC_POSITIONS (crystal)
>>> Mn1 0.000000000 0.000000000000 0.000000000
>>> Mn2 0.333333333 0.666666666667 0.500000000
>>> Se 0.000000000 0.000000000000 0.345000000
>>> Se 0.333333333 0.666666666667 0.845000000
>>> K_POINTS (automatic)
>>> 6 6 4 0 0 0
>>>
>>> *OUTPUT FOR WURTZITE*
>>>
>>> End of BFGS Geometry Optimization
>>>
>>> Final enthalpy = -464.4799667612 Ry
>>> Begin final coordinates
>>> new unit-cell volume = 681.36082 a.u.^3 ( 100.96726 Ang^3 )
>>>
>>> CELL_PARAMETERS (alat= 7.89527578)
>>> 1.001414763 0.000000000 0.000000000
>>> -0.500707382 0.867250625 0.000000000
>>> 0.000000000 0.000000000 1.594103933
>>>
>>> ATOMIC_POSITIONS (crystal)
>>> Mn1 0.000000000 0.000000000 -0.014999731
>>> Mn2 0.333333333 0.666666667 0.485592670
>>> Se 0.000000000 0.000000000 0.359333481
>>> Se 0.333333333 0.666666667 0.860073579
>>> End final coordinates
>>>
>>>
>>>
>>>
>>>
>>> --
>>> Regards,
>>> MOHNISH,
>>> -----------------------------------------------------------------
>>> Mohnish Pandey
>>> Y6927262,5th Year dual degree student,
>>> Department of Chemical Engineering,
>>> IIT KANPUR, UP, INDIA
>>> -----------------------------------------------------------------
>>>
>>> _______________________________________________
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
>>> http://www.democritos.it/mailman/listinfo/pw_forum
>>>
>>>
>>
>> --
>> Jia Chen
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>> ------------------------------
>>
>> Message: 2
>> Date: Fri, 21 Jan 2011 08:10:41 +0100
>> From: "Lorenzo Paulatto"<lorenzo.paulatto at impmc.upmc.fr>
>> Subject: Re: [Pw_forum] a question about MnSe
>> To: "PWSCF Forum"<pw_forum at pwscf.org>
>> Message-ID:<op.vpncv1mm5jfbqb at paulax>
>> Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes
>>
>> In data 20 gennaio 2011 alle ore 19:37:16, jia chen
>> <jiachen at princeton.edu> ha scritto:
>>> I also have a question about vc-relax. How do you know if your cutoff is
>>> large enough to overcome Pulay stress, or you can do something else to
>>> get
>>> rid of it in you calculations. Thanks.
>> The vc-relax algorithm keeps number of plane waves constant (i.e. it
>> changes ecutwfc as ~ V^3/2) in order to avoid Pulay stress.
>>
>> best regards
>>
>>
>> --
>> Lorenzo Paulatto
>> post-doc @ IMPMC/UPMC - Universit? Paris 6
>> phone: +33 (0)1 44 27 74 89
>> www: http://www-int.impmc.upmc.fr/~paulatto/
>>
>> previously (take note of the change!):
>> phd student @ SISSA& DEMOCRITOS (Trieste)
>> phone: +39 040 3787 511
>> www: http://people.sissa.it/~paulatto/
>>
>>
>> ------------------------------
>>
>> Message: 3
>> Date: Fri, 21 Jan 2011 13:00:16 +0530
>> From: mohnish pandey<mohnish.iitk at gmail.com>
>> Subject: Re: [Pw_forum] a question about MnSe
>> To: PWSCF Forum<pw_forum at pwscf.org>
>> Message-ID:
>> <AANLkTikazpo9j53oUmWw_CFoLh=_KYzaVWLbPP72CECB at mail.gmail.com>
>> Content-Type: text/plain; charset="iso-8859-1"
>>
>> Dear Lorenzo !
>> Can you give me a direction for my question about
>> MnSe. I am really struck in it...
>>
>> On Fri, Jan 21, 2011 at 12:40 PM, Lorenzo Paulatto<
>> lorenzo.paulatto at impmc.upmc.fr> wrote:
>>
>>> In data 20 gennaio 2011 alle ore 19:37:16, jia chen
>>> <jiachen at princeton.edu> ha scritto:
>>>> I also have a question about vc-relax. How do you know if your cutoff
>> is
>>>> large enough to overcome Pulay stress, or you can do something else to
>>>> get
>>>> rid of it in you calculations. Thanks.
>>> The vc-relax algorithm keeps number of plane waves constant (i.e. it
>>> changes ecutwfc as ~ V^3/2) in order to avoid Pulay stress.
>>>
>>> best regards
>>>
>>>
>>> --
>>> Lorenzo Paulatto
>>> post-doc @ IMPMC/UPMC - Universit? Paris 6
>>> phone: +33 (0)1 44 27 74 89
>>> www: http://www-int.impmc.upmc.fr/~paulatto/
>>>
>>> previously (take note of the change!):
>>> phd student @ SISSA& DEMOCRITOS (Trieste)
>>> phone: +39 040 3787 511
>>> www: http://people.sissa.it/~paulatto/
>>> _______________________________________________
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
>>> http://www.democritos.it/mailman/listinfo/pw_forum
>>>
>>
>>
>> --
>> Regards,
>> MOHNISH,
>> -----------------------------------------------------------------
>> Mohnish Pandey
>> Y6927262,5th Year dual degree student,
>> Department of Chemical Engineering,
>> IIT KANPUR, UP, INDIA
>> -----------------------------------------------------------------
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>> ------------------------------
>>
>> Message: 4
>> Date: Fri, 21 Jan 2011 13:44:05 +0530
>> From: Prasenjit Ghosh<prasenjit.jnc at gmail.com>
>> Subject: Re: [Pw_forum] a question about MnSe
>> To: PWSCF Forum<pw_forum at pwscf.org>
>> Message-ID:
>> <AANLkTinESV_Kk7=FUEDkM41J=ywHbi7wo_+ykj=-Pra3 at mail.gmail.com>
>> Content-Type: text/plain; charset=ISO-8859-1
>>
>> Dear Mohnish,
>>
>> One thing you may try to do is to change the value of starting
>> magnetization and redo the calculation.
>> Sometimes in case of magnetic systems (at least those which are
>> ferromagnetic), the code gets stuck into some local minima. Starting
>> from a different point might help you to reach the correct ground
>> state.
>>
>> Prasenjit
>>
>> On 21 January 2011 13:00, mohnish pandey<mohnish.iitk at gmail.com> wrote:
>>> Dear Lorenzo !
>>> ?? ? ? ? ? ? ? ? ? ? ? ?Can you give me a direction for my question about
>>> MnSe. I am really struck in it...
>>>
>>> On Fri, Jan 21, 2011 at 12:40 PM, Lorenzo Paulatto
>>> <lorenzo.paulatto at impmc.upmc.fr> wrote:
>>>> In data 20 gennaio 2011 alle ore 19:37:16, jia chen
>>>> <jiachen at princeton.edu> ha scritto:
>>>>> I also have a question about vc-relax. How do you know if your cutoff
>> is
>>>>> large enough to overcome Pulay stress, or you can do something else to
>>>>> get
>>>>> rid of it in you calculations. Thanks.
>>>> The vc-relax algorithm keeps number of plane waves constant (i.e. it
>>>> changes ecutwfc as ~ V^3/2) in order to avoid Pulay stress.
>>>>
>>>> best regards
>>>>
>>>>
>>>> --
>>>> Lorenzo Paulatto
>>>> post-doc @ IMPMC/UPMC - Universit? Paris 6
>>>> phone: +33 (0)1 44 27 74 89
>>>> www: ? http://www-int.impmc.upmc.fr/~paulatto/
>>>>
>>>> previously (take note of the change!):
>>>> phd student @ SISSA ?& ?DEMOCRITOS (Trieste)
>>>> phone: +39 040 3787 511
>>>> www: ? http://people.sissa.it/~paulatto/
>>>> _______________________________________________
>>>> Pw_forum mailing list
>>>> Pw_forum at pwscf.org
>>>> http://www.democritos.it/mailman/listinfo/pw_forum
>>>
>>>
>>> --
>>> Regards,
>>> MOHNISH,
>>> -----------------------------------------------------------------
>>> Mohnish Pandey
>>> Y6927262,5th Year dual degree student,
>>> Department of Chemical Engineering,
>>> IIT KANPUR, UP, INDIA
>>> -----------------------------------------------------------------
>>>
>>> _______________________________________________
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
>>> http://www.democritos.it/mailman/listinfo/pw_forum
>>>
>>>
>>
>>
>> --
>> PRASENJIT GHOSH,
>> Assistant Professor,
>> IISER Pune,
>> First floor, Central Tower, Sai Trinity Building
>> Garware Circle, Sutarwadi, Pashan
>> Pune, Maharashtra 411021, India
>>
>> Phone: +91 (20) 2590 8203
>> Fax: +91 (20) 2589 9790
>>
>>
>> ------------------------------
>>
>> _______________________________________________
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://www.democritos.it/mailman/listinfo/pw_forum
>>
>>
>> End of Pw_forum Digest, Vol 43, Issue 37
>> ****************************************
>>
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