subject:"\[Pw_forum\] London Dispersion force\: DFT\-D2"

[Pw_forum] London Dispersion force: DFT-D2

2016-05-02 Thread Elliot Menkah

Hi all,
I'm trying to account for  the energy contribution of London dispersion
forces on the total energy of a hydrazine-nickel system.

Could someone please assist me as to how to account for London
dispersion forces with QE or essentially how to do a DFT-D2 calculation
with the the aim of accounting for the energy contribution of dispersion
forces.

When I correct the net-surface dipole on a system by using the variables
and values below, does it affect the energy from dispersion forces, if
so, how?
How does correcting the net-surface dipole relate to accounting for
dispersion forces?

--
&CONTROL
tefield = .TRUE.,
   dipfield = .TRUE.,
   disk_io = 'low',

&SYSTEM
   edir=3,
   emaxpos=0.65,
   eopreg=0.06,
   eamp=0,
--


I'm basically trying to account for London dispersion forces on a
hydrazine-nickel system.
Any info to help my computation would be gladly appreciated.
Thank you

Kind Regards,
Elliot

-- 
Elliot S. Menkah, AMRSC
Research Student - Computational Chemistry/ Computational Material Science
Theoretical and Computational Chemistry Lab.
Dept. of Chemistry
Kwame Nkrumah University of Sci. and Tech.
Kumasi
Ghana

Tel: +233 243-055-717

Alt Email: esmen...@knust.edu.gh
   elliotsmen...@gmail.com
   elliotsmen...@hotmail.com



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Re: [Pw_forum] London Dispersion force: DFT-D2

2016-05-03 Thread Giuseppe Mattioli


Dear Elliot
I do not know if I understand well your questions, but I try to answer:

> Could someone please assist me as to how to account for London
> dispersion forces with QE or essentially how to do a DFT-D2 calculation
> with the the aim of accounting for the energy contribution of dispersion
> forces.

Use vdw_corr='grimme-d2'
You will find in the output the dispersion force contribution to the total 
energy:

!total energy  =   -2369.89004091 Ry
 Harris-Foulkes estimate   =   -2369.89004090 Ry
 estimated scf accuracy<   0.0001 Ry

 The total energy is the sum of the following terms:

 one-electron contribution =  -22567.16723495 Ry
 hartree contribution  =   11423.49753189 Ry
 xc contribution   =-757.0298 Ry
 ewald contribution=9530.66102736 Ry
 Dispersion Correction =  -0.98373910 Ry
 Hubbard energy=   1.13399751 Ry
 smearing contrib. (-TS)   =  -0.00195694 Ry

> I'm trying to account for  the energy contribution of London dispersion
> forces on the total energy of a hydrazine-nickel system.

Remember that DFT-D2 badly overestimate the interaction of molecules with metal 
surfaces, see Grimme, S.; Antony, J.; Ehrlich, S.; Krieg, H. A 
consistent and accurate ab initio parametrization of density functional 
dispersion correction (DFT-D) for the 94 elements H-Pu. J. Chem. Phys. 2010, 
132, 154104. In cases such as N2H2 on Ni I would rather use vdwdf or vdwdf-c09 
(see usage and related papers in QE documentation).

> --
> &CONTROL
> tefield = .TRUE.,
>dipfield = .TRUE.,
>disk_io = 'low',
> 
> &SYSTEM
>edir=3,
>emaxpos=0.65,
>eopreg=0.06,
>eamp=0,
> --
> 

This is a well tested but old and complex machine to correct the interaction of 
a dipole with its periodic replicas along z. I do not know if it is 
possible to estimate its impact on dispersion forces in a different way than by 
using/not using the dipole correction and check the difference between 
the above "Dispersion Correction" contribution to the total energy. However, 
I've satisfactorily used for a system similar to yours (thiol SAM on Au 
surface) this new setup (again, read the documentation and related papers), 
which decouple in a simpler way the dipole along z.

 &system
input_dft='vdw-df-c09'
assume_isolated = 'esm',
esm_bc='bc1',
 /

HTH
Giuseppe


On Tuesday, May 03, 2016 12:41:49 AM Elliot Menkah wrote:
> Hi all,
> I'm trying to account for  the energy contribution of London dispersion
> forces on the total energy of a hydrazine-nickel system.
> 
> Could someone please assist me as to how to account for London
> dispersion forces with QE or essentially how to do a DFT-D2 calculation
> with the the aim of accounting for the energy contribution of dispersion
> forces.
> 
> When I correct the net-surface dipole on a system by using the variables
> and values below, does it affect the energy from dispersion forces, if
> so, how?
> How does correcting the net-surface dipole relate to accounting for
> dispersion forces?
> 
> --
> &CONTROL
> tefield = .TRUE.,
>dipfield = .TRUE.,
>disk_io = 'low',
> 
> &SYSTEM
>edir=3,
>emaxpos=0.65,
>eopreg=0.06,
>eamp=0,
> --
> 
> 
> I'm basically trying to account for London dispersion forces on a
> hydrazine-nickel system.
> Any info to help my computation would be gladly appreciated.
> Thank you
> 
> Kind Regards,
> Elliot


- Article premier - Les hommes naissent et demeurent
libres et égaux en droits. Les distinctions sociales
ne peuvent être fondées que sur l'utilité commune
- Article 2 - Le but de toute association politique
est la conservation des droits naturels et 
imprescriptibles de l'homme. Ces droits sont la liberté,
la propriété, la sûreté et la résistance à l'oppression.


   Giuseppe Mattioli
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA   
   v. Salaria Km 29,300 - C.P. 10
   I 00015 - Monterotondo Stazione (RM), Italy
   Tel + 39 06 90672836 - Fax +39 06 90672316
   E-mail: 
   http://www.ism.cnr.it/en/staff/giuseppe-mattioli/
   ResearcherID: F-6308-2012

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Re: [Pw_forum] London Dispersion force: DFT-D2

2016-05-03 Thread Martin Andersson

Hi Elliot,

Indeed, standard DFT-D2 does overestimate adsorption on metals, but a modified 
DFT-D2 version that I published doesn’t ;)

http://www.hindawi.com/journals/jtc/2013/327839/ 


I haven’t tried adsorption onto Ni surfaces specifically, but bulk Ni 
properties came out fine and adsorption on quite a few other metals (including 
Pt, Au, etc) gives quite reasonable results. In fact, it would be quite 
interesting for me to see if adsorption on Ni behaves as well as other 
surfaces, so by all means, try it out.

I don’t use the vdw functionals in my research and have only read up on their 
progress briefly, but as far as I understood, they were not able to handle spin 
polarised systems initially, like Ni. Can anyone enlighten me on the status of 
vdw functionals for spin polarised calculations?

Cheers,

Martin P. Andersson
Associate Professor
Nano-Science Center, Department of Chemistry
University of Copenhagen, Denmark

Tel: +45 3532 0280
Mobile: +46 733 893091
E-mail: m...@nano.ku.dk











> On 03 May 2016, at 10:26, Giuseppe Mattioli  
> wrote:
> 
> 
> Dear Elliot
> I do not know if I understand well your questions, but I try to answer:
> 
>> Could someone please assist me as to how to account for London
>> dispersion forces with QE or essentially how to do a DFT-D2 calculation
>> with the the aim of accounting for the energy contribution of dispersion
>> forces.
> 
> Use vdw_corr='grimme-d2'
> You will find in the output the dispersion force contribution to the total 
> energy:
> 
> !total energy  =   -2369.89004091 Ry
> Harris-Foulkes estimate   =   -2369.89004090 Ry
> estimated scf accuracy<   0.0001 Ry
> 
> The total energy is the sum of the following terms:
> 
> one-electron contribution =  -22567.16723495 Ry
> hartree contribution  =   11423.49753189 Ry
> xc contribution   =-757.0298 Ry
> ewald contribution=9530.66102736 Ry
> Dispersion Correction =  -0.98373910 Ry
> Hubbard energy=   1.13399751 Ry
> smearing contrib. (-TS)   =  -0.00195694 Ry
> 
>> I'm trying to account for  the energy contribution of London dispersion
>> forces on the total energy of a hydrazine-nickel system.
> 
> Remember that DFT-D2 badly overestimate the interaction of molecules with 
> metal surfaces, see Grimme, S.; Antony, J.; Ehrlich, S.; Krieg, H. A 
> consistent and accurate ab initio parametrization of density functional 
> dispersion correction (DFT-D) for the 94 elements H-Pu. J. Chem. Phys. 2010, 
> 132, 154104. In cases such as N2H2 on Ni I would rather use vdwdf or 
> vdwdf-c09 (see usage and related papers in QE documentation).
> 
>> --
>> &CONTROL
>> tefield = .TRUE.,
>>   dipfield = .TRUE.,
>>   disk_io = 'low',
>> 
>> &SYSTEM
>>   edir=3,
>>   emaxpos=0.65,
>>   eopreg=0.06,
>>   eamp=0,
>> --
>> 
> 
> This is a well tested but old and complex machine to correct the interaction 
> of a dipole with its periodic replicas along z. I do not know if it is 
> possible to estimate its impact on dispersion forces in a different way than 
> by using/not using the dipole correction and check the difference between 
> the above "Dispersion Correction" contribution to the total energy. However, 
> I've satisfactorily used for a system similar to yours (thiol SAM on Au 
> surface) this new setup (again, read the documentation and related papers), 
> which decouple in a simpler way the dipole along z.
> 
> &system
>input_dft='vdw-df-c09'
>assume_isolated = 'esm',
>esm_bc='bc1',
> /
> 
> HTH
> Giuseppe
> 
> 
> On Tuesday, May 03, 2016 12:41:49 AM Elliot Menkah wrote:
>> Hi all,
>> I'm trying to account for  the energy contribution of London dispersion
>> forces on the total energy of a hydrazine-nickel system.
>> 
>> Could someone please assist me as to how to account for London
>> dispersion forces with QE or essentially how to do a DFT-D2 calculation
>> with the the aim of accounting for the energy contribution of dispersion
>> forces.
>> 
>> When I correct the net-surface dipole on a system by using the variables
>> and values below, does it affect the energy from dispersion forces, if
>> so, how?
>> How does correcting the net-surface dipole relate to accounting for
>> dispersion forces?
>> 
>> --
>> &CONTROL
>> tefield = .TRUE.,
>>   dipfield = .TRUE.,
>>   disk_io = 'low',
>> 
>> &SYSTEM
>>   edir=3,
>>   emaxpos=0.65,
>>   eopreg=0.06,
>>   eamp=0,
>> --
>> 
>> 
>> I'm basically trying to account for London dispersion forces on a
>> hydrazine-nickel system.
>> Any info to help my computation would be gladly appreciated.
>> Thank you
>> 
>> Kind Regards,
>> Elliot
> 
> **

Re: [Pw_forum] London Dispersion force: DFT-D2

2016-05-03 Thread Giuseppe Mattioli


Dear Martin
There is a brand-new implementation of vdwdf by Thonhauser and his group 
(Thonhauser, T.; Zuluaga, S.; Arter, C. A.; Berland, K.; Schröder, E.; 
Hyldgaard, P. Spin Signature of Nonlocal Correlation Binding in Metal-Organic 
Frameworks. Phys. Rev. Lett. 2015, 115, 136402) which handles well open-
shell systems. It has been added to v 5.2.1 or v 5.3.0. Time ago I did some 
"handmade correction" to DFT-D2 to investigate the absorption of zinc 
phthalocianine on ZnO by using some force-field derived (AMBER or CHARMM, I do 
not remember well) C6 coefficients. I ended in using vdwdf, though...
HTH
Giuseppe

On Tuesday, May 03, 2016 10:56:54 AM Martin Andersson wrote:
> Hi Elliot,
> 
> Indeed, standard DFT-D2 does overestimate adsorption on metals, but a 
> modified DFT-D2 version that I published doesnât ;)
> 
> http://www.hindawi.com/journals/jtc/2013/327839/ 
> 
> 
> I havenât tried adsorption onto Ni surfaces specifically, but bulk Ni 
> properties came out fine and adsorption on quite a few other metals (including
> Pt, Au, etc) gives quite reasonable results. In fact, it would be quite 
> interesting for me to see if adsorption on Ni behaves as well as other
> surfaces, so by all means, try it out.
> 
> I donât use the vdw functionals in my research and have only read up on 
> their progress briefly, but as far as I understood, they were not able to
> handle spin polarised systems initially, like Ni. Can anyone enlighten me on 
> the status of vdw functionals for spin polarised calculations?
> 
> Cheers,
> ââââââââââââââââââââââââ
> Martin P. Andersson
> Associate Professor
> Nano-Science Center, Department of Chemistry
> University of Copenhagen, Denmark
> 
> Tel: +45 3532 0280
> Mobile: +46 733 893091
> E-mail: m...@nano.ku.dk
> ââââââââââââââââââââââââ
> 
> > On 03 May 2016, at 10:26, Giuseppe Mattioli  
> > wrote:
> > 
> > 
> > Dear Elliot
> > 
> > I do not know if I understand well your questions, but I try to answer:
> >> Could someone please assist me as to how to account for London
> >> dispersion forces with QE or essentially how to do a DFT-D2 calculation
> >> with the the aim of accounting for the energy contribution of dispersion
> >> forces.
> > 
> > Use vdw_corr='grimme-d2'
> > You will find in the output the dispersion force contribution to the total 
> > energy:
> > 
> > !total energy  =   -2369.89004091 Ry
> > 
> > Harris-Foulkes estimate   =   -2369.89004090 Ry
> > estimated scf accuracy<   0.0001 Ry
> > 
> > The total energy is the sum of the following terms:
> > 
> > one-electron contribution =  -22567.16723495 Ry
> > hartree contribution  =   11423.49753189 Ry
> > xc contribution   =-757.0298 Ry
> > ewald contribution=9530.66102736 Ry
> > Dispersion Correction =  -0.98373910 Ry
> > Hubbard energy=   1.13399751 Ry
> > smearing contrib. (-TS)   =  -0.00195694 Ry
> >> 
> >> I'm trying to account for  the energy contribution of London dispersion
> >> forces on the total energy of a hydrazine-nickel system.
> > 
> > Remember that DFT-D2 badly overestimate the interaction of molecules with 
> > metal surfaces, see Grimme, S.; Antony, J.; Ehrlich, S.; Krieg, H. A
> > consistent and accurate ab initio parametrization of density functional 
> > dispersion correction (DFT-D) for the 94 elements H-Pu. J. Chem. Phys.
> > 2010, 132, 154104. In cases such as N2H2 on Ni I would rather use vdwdf or 
> > vdwdf-c09 (see usage and related papers in QE documentation).
> > 
> >> --
> >> &CONTROL
> >> tefield = .TRUE.,
> >> 
> >>   dipfield = .TRUE.,
> >>   disk_io = 'low',
> >> 
> >> &SYSTEM
> >> 
> >>   edir=3,
> >>   emaxpos=0.65,
> >>   eopreg=0.06,
> >>   eamp=0,
> >> 
> >> --
> > 
> > This is a well tested but old and complex machine to correct the 
> > interaction of a dipole with its periodic replicas along z. I do not know 
> > if it
> > is
> > possible to estimate its impact on dispersion forces in a different way 
> > than by using/not using the dipole correction and check the difference
> > between the above "Dispersion Correction" contribution to the total energy. 
> > However, I've satisfactorily used for a system similar to yours
> > (thiol SAM on Au surface) this new setup (again, read the documentation and 
> > related papers), which decouple in a simpler way the dipole along z.
> > 
> > &system
> > 
> >input_dft='vdw-df-c09'
> >assume_isolated = 'esm',
> >esm_bc='bc1',
> > 
> > /
> > 
> > HTH
> > Giuseppe
> > 
> > On Tuesday, May 03, 2016 12:41:49 AM Elliot Menkah wrote:
> >> Hi all,
> >> I'm trying to account for  the energy contribution of London dispersion
> >> forces on the total energy of a hydrazin

Re: [Pw_forum] London Dispersion force: DFT-D2

2016-05-03 Thread Marzari Nicola


. Can anyone enlighten me on the status of vdw functionals for spin polarised 
calculations?



This prl http://arxiv.org/abs/1509.03759 - nicola


Cheers,

Martin P. Andersson
Associate Professor
Nano-Science Center, Department of Chemistry
University of Copenhagen, Denmark

Tel: +45 3532 0280
Mobile: +46 733 893091
E-mail: m...@nano.ku.dk











On 03 May 2016, at 10:26, Giuseppe Mattioli 
mailto:giuseppe.matti...@ism.cnr.it>> wrote:


Dear Elliot
I do not know if I understand well your questions, but I try to answer:

Could someone please assist me as to how to account for London
dispersion forces with QE or essentially how to do a DFT-D2 calculation
with the the aim of accounting for the energy contribution of dispersion
forces.

Use vdw_corr='grimme-d2'
You will find in the output the dispersion force contribution to the total 
energy:

!total energy  =   -2369.89004091 Ry
Harris-Foulkes estimate   =   -2369.89004090 Ry
estimated scf accuracy<   0.0001 Ry

The total energy is the sum of the following terms:

one-electron contribution =  -22567.16723495 Ry
hartree contribution  =   11423.49753189 Ry
xc contribution   =-757.0298 Ry
ewald contribution=9530.66102736 Ry
Dispersion Correction =  -0.98373910 Ry
Hubbard energy=   1.13399751 Ry
smearing contrib. (-TS)   =  -0.00195694 Ry

I'm trying to account for  the energy contribution of London dispersion
forces on the total energy of a hydrazine-nickel system.

Remember that DFT-D2 badly overestimate the interaction of molecules with metal 
surfaces, see Grimme, S.; Antony, J.; Ehrlich, S.; Krieg, H. A
consistent and accurate ab initio parametrization of density functional 
dispersion correction (DFT-D) for the 94 elements H-Pu. J. Chem. Phys. 2010,
132, 154104. In cases such as N2H2 on Ni I would rather use vdwdf or vdwdf-c09 
(see usage and related papers in QE documentation).

--
&CONTROL
tefield = .TRUE.,
  dipfield = .TRUE.,
  disk_io = 'low',

&SYSTEM
  edir=3,
  emaxpos=0.65,
  eopreg=0.06,
  eamp=0,
--


This is a well tested but old and complex machine to correct the interaction of 
a dipole with its periodic replicas along z. I do not know if it is
possible to estimate its impact on dispersion forces in a different way than by 
using/not using the dipole correction and check the difference between
the above "Dispersion Correction" contribution to the total energy. However, 
I've satisfactorily used for a system similar to yours (thiol SAM on Au
surface) this new setup (again, read the documentation and related papers), 
which decouple in a simpler way the dipole along z.

&system
   input_dft='vdw-df-c09'
   assume_isolated = 'esm',
   esm_bc='bc1',
/

HTH
Giuseppe


On Tuesday, May 03, 2016 12:41:49 AM Elliot Menkah wrote:
Hi all,
I'm trying to account for  the energy contribution of London dispersion
forces on the total energy of a hydrazine-nickel system.

Could someone please assist me as to how to account for London
dispersion forces with QE or essentially how to do a DFT-D2 calculation
with the the aim of accounting for the energy contribution of dispersion
forces.

When I correct the net-surface dipole on a system by using the variables
and values below, does it affect the energy from dispersion forces, if
so, how?
How does correcting the net-surface dipole relate to accounting for
dispersion forces?

--
&CONTROL
tefield = .TRUE.,
  dipfield = .TRUE.,
  disk_io = 'low',

&SYSTEM
  edir=3,
  emaxpos=0.65,
  eopreg=0.06,
  eamp=0,
--


I'm basically trying to account for London dispersion forces on a
hydrazine-nickel system.
Any info to help my computation would be gladly appreciated.
Thank you

Kind Regards,
Elliot


- Article premier - Les hommes naissent et demeurent
libres et égaux en droits. Les distinctions sociales
ne peuvent être fondées que sur l'utilité commune
- Article 2 - Le but de toute association politique
est la conservation des droits naturels et
imprescriptibles de l'homme. Ces droits sont la liberté,
la propriété, la sûreté et la résistance à l'oppression.


  Giuseppe Mattioli
  CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
  v. Salaria Km 29,300 - C.P. 10
  I 00015 - Monterotondo Stazione (RM), Italy
  Tel + 39 06 90672836 - Fax +39 06 90672316
  E-mail: mailto:giuseppe.matti...@ism.cnr.it>>
  http://www.ism.cnr.it/en/staff/giuseppe-mattioli/
  ResearcherID: F-6308-2012

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Re: [Pw_forum] London Dispersion force: DFT-D2

2016-05-03 Thread Francesco Pelizza

Hi Elliot,

with this two commands in the '&system' card: vdw_corr='DFT-D', 
london_s6=0.75,

you can do the job of using D2, please note that 0.75 is the default 
value for PBE (GGA)

see web page for further detail:
http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#idm6241264

Francesco



On 03/05/16 01:41, Elliot Menkah wrote:
> Hi all,
> I'm trying to account for  the energy contribution of London dispersion
> forces on the total energy of a hydrazine-nickel system.
>
> Could someone please assist me as to how to account for London
> dispersion forces with QE or essentially how to do a DFT-D2 calculation
> with the the aim of accounting for the energy contribution of dispersion
> forces.
>
> When I correct the net-surface dipole on a system by using the variables
> and values below, does it affect the energy from dispersion forces, if
> so, how?
> How does correcting the net-surface dipole relate to accounting for
> dispersion forces?
>
> --
> &CONTROL
> tefield = .TRUE.,
> dipfield = .TRUE.,
> disk_io = 'low',
>
> &SYSTEM
> edir=3,
> emaxpos=0.65,
> eopreg=0.06,
> eamp=0,
> --
>
>
> I'm basically trying to account for London dispersion forces on a
> hydrazine-nickel system.
> Any info to help my computation would be gladly appreciated.
> Thank you
>
> Kind Regards,
> Elliot
>

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Re: [Pw_forum] London Dispersion force: DFT-D2

2016-05-03 Thread Elliot S. MENKAH

Thank you  all for the invaluable help.

I would implement what has been shared and repost should I need further
help.

Thank you.

Kind Regards,
Elliot


On 05/03/2016 09:24 AM, Marzari Nicola wrote:
>
>> . Can anyone enlighten me on the status of vdw functionals for spin
>> polarised calculations?
>>
>
>
> This prl http://arxiv.org/abs/1509.03759 - nicola
>
>
>> Cheers,
>> 
>> Martin P. Andersson
>> Associate Professor
>> Nano-Science Center, Department of Chemistry
>> University of Copenhagen, Denmark
>>
>> Tel: +45 3532 0280
>> Mobile: +46 733 893091
>> E-mail: m...@nano.ku.dk 
>> 
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>> On 03 May 2016, at 10:26, Giuseppe Mattioli
>>> mailto:giuseppe.matti...@ism.cnr.it>>
>>> wrote:
>>>
>>>
>>> Dear Elliot
>>> I do not know if I understand well your questions, but I try to answer:
>>>
 Could someone please assist me as to how to account for London
 dispersion forces with QE or essentially how to do a DFT-D2 calculation
 with the the aim of accounting for the energy contribution of
 dispersion
 forces.
>>>
>>> Use vdw_corr='grimme-d2'
>>> You will find in the output the dispersion force contribution to the
>>> total energy:
>>>
>>> !total energy  =   -2369.89004091 Ry
>>> Harris-Foulkes estimate   =   -2369.89004090 Ry
>>> estimated scf accuracy<   0.0001 Ry
>>>
>>> The total energy is the sum of the following terms:
>>>
>>> one-electron contribution =  -22567.16723495 Ry
>>> hartree contribution  =   11423.49753189 Ry
>>> xc contribution   =-757.0298 Ry
>>> ewald contribution=9530.66102736 Ry
>>> Dispersion Correction =  -0.98373910 Ry
>>> Hubbard energy=   1.13399751 Ry
>>> smearing contrib. (-TS)   =  -0.00195694 Ry
>>>
 I'm trying to account for  the energy contribution of London dispersion
 forces on the total energy of a hydrazine-nickel system.
>>>
>>> Remember that DFT-D2 badly overestimate the interaction of molecules
>>> with metal surfaces, see Grimme, S.; Antony, J.; Ehrlich, S.; Krieg,
>>> H. A 
>>> consistent and accurate ab initio parametrization of density
>>> functional dispersion correction (DFT-D) for the 94 elements H-Pu.
>>> J. Chem. Phys. 2010, 
>>> 132, 154104. In cases such as N2H2 on Ni I would rather use vdwdf or
>>> vdwdf-c09 (see usage and related papers in QE documentation).
>>>
 --
 &CONTROL
 tefield = .TRUE.,
   dipfield = .TRUE.,
   disk_io = 'low',

 &SYSTEM
   edir=3,
   emaxpos=0.65,
   eopreg=0.06,
   eamp=0,
 --

>>>
>>> This is a well tested but old and complex machine to correct the
>>> interaction of a dipole with its periodic replicas along z. I do not
>>> know if it is 
>>> possible to estimate its impact on dispersion forces in a different
>>> way than by using/not using the dipole correction and check the
>>> difference between 
>>> the above "Dispersion Correction" contribution to the total energy.
>>> However, I've satisfactorily used for a system similar to yours
>>> (thiol SAM on Au 
>>> surface) this new setup (again, read the documentation and related
>>> papers), which decouple in a simpler way the dipole along z.
>>>
>>> &system
>>>input_dft='vdw-df-c09'
>>>assume_isolated = 'esm',
>>>esm_bc='bc1',
>>> /
>>>
>>> HTH
>>> Giuseppe
>>>
>>>
>>> On Tuesday, May 03, 2016 12:41:49 AM Elliot Menkah wrote:
 Hi all,
 I'm trying to account for  the energy contribution of London dispersion
 forces on the total energy of a hydrazine-nickel system.

 Could someone please assist me as to how to account for London
 dispersion forces with QE or essentially how to do a DFT-D2 calculation
 with the the aim of accounting for the energy contribution of
 dispersion
 forces.

 When I correct the net-surface dipole on a system by using the
 variables
 and values below, does it affect the energy from dispersion forces, if
 so, how?
 How does correcting the net-surface dipole relate to accounting for
 dispersion forces?

 --
 &CONTROL
 tefield = .TRUE.,
   dipfield = .TRUE.,
   disk_io = 'low',

 &SYSTEM
   edir=3,
   emaxpos=0.65,
   eopreg=0.06,
   eamp=0,
 --


 I'm basically trying to account for London dispersion forces on a
 hydrazine-nickel system.
 Any info to help my computation would be gladly appreciated.
 Thank you

 Kind Regards,
 Elliot
>>>
>>> 
>>> - Article premier - Les hommes naissent et demeurent
>>> libres et égaux en droits. Les distinctions sociales
>>> ne peuvent être fondées que

[Pw_forum] London Dispersion force: DFT-D2

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