From owner-chemistry@ccl.net Tue Sep 1 10:44:01 2015 From: "Thomas Manz thomasamanz-x-gmail.com" To: CCL Subject: CCL: NBO vs Loewdin Charges Message-Id: <-51646-150901103842-6392-6luLcmXK8k2VadO2OsR0oQ!^!server.ccl.net> X-Original-From: Thomas Manz Content-Type: multipart/alternative; boundary=001a1146f0f85bb4b5051eb081f5 Date: Tue, 1 Sep 2015 08:38:36 -0600 MIME-Version: 1.0 Sent to CCL by: Thomas Manz [thomasamanz]![gmail.com] --001a1146f0f85bb4b5051eb081f5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable I think what is meant is that if you represent the electron density correctly, the net atomic charges should be independent of the basis set used. Methods that do not satisfy this property (such as Mulliken populations) are non-physical and should be discarded. It is possible to construct atomic population analysis methods in which the atomic populations depend only on the electron and spin density distributions with no explicit basis set dependence. In this latter case, even an experimentally measured electron distribution could be used as input without requiring a "basis set" at all. Sincerely, Tom On Mon, Aug 31, 2015 at 11:06 PM, Dr. Robert Molt Jr. r.molt.chemical.physics+/-gmail.com wrote: > Atomic charge models are not basis independent; see Chris Cramer's book, > chapter 9, p.314. Some models give charges which are consistent with > increasing basis set size, some are not, but all depend on the basis. > > If you have anions, you cannot describe the density correctly without > diffuse functions; this is a basis set dependence. > > Dr. Robert Molt Jr.r.molt.chemical.physics]-[gmail.com > > On 08/31/2015 11:14 PM, John McKelvey jmmckel(a)gmail.com wrote: > > Hello, > > There is a paper from a group in Germany demonstrating essentially basis > set independence of atomic charges.... Terrible to say that while I > remember the paper, and that the method has been installed in ORCA for th= e > next release, I will have to search for the paper... just moved from > Indiana to Missouri so things are in a bit of disarray. > > Maybe someone has seen this paper? > > > John > > > On Mon, Aug 31, 2015 at 5:47 PM, V=C3=ADctor Lua=C3=B1a Cabal > victor_-_fluor.quimica.uniovi.es wrote: > >> >> Sent to CCL by: =3D?iso-8859-1?Q?V=3DEDctor_Lua=3DF1a?=3D Cabal [victor = ~~ >> fluor.quimica.uniovi.es] >> On Mon, Aug 31, 2015 at 04:22:51PM -0400, Jim Kress >> jimkress35-x-gmail.com wrote: >> > >> > Sent to CCL by: "Jim Kress" [jimkress35]-[gmail.com] >> > Did you use an ECP for Plutonium and if so, was it properly represente= d >> in >> > the AIM analysis? >> >> Jim, >> >> QTAIM should refer to the all electron density. However there have >> been explorations of using ECP valence densities and they can work if >> you do it carefully. You can either add the core contributions to the >> valence density (it works) or be advise that your electron density is >> not complete, so there are properties of the real QTAIM analysis that >> can not work. >> >> For instance, the basins and the topological partition of the full >> electron density (rho) is not equivalent if you are using only the >> valence component (val-rho). >> >> However, if the basins are well defined there is no problem in >> integrating the valence density within the full electron rho. The same >> can be said for the analysis of spin components, and so on. >> Using the critic2 code a lot of strange numerical experiments of >> this kind can be easily performed. The code also has techniques to >> fulfill the valence density with core components. >> >> Read on critic2 in this ref. >> >> A. Otero-de-la-Roza et al, Comput phys Commun 182 (2013) 2232--2248 >> >> An updated version of the code and manual can be found on >> >> >> >> >> I may look for old work published on this subject, if you are truly >> interested. >> >> Best regards, >> V=C3=ADctor Lua=C3=B1a >> -- >> . . "In science a person can be convinced by a good argument. >> / `' \ That is almost impossible in politics or religion" >> /(o)(o)\ (Adapted from Carl Sagan) >> /`. \/ .'\ "Lo mediocre es peor que lo bueno, pero tambi=C3=A9n es pe= or >> / '`'` \ que lo malo, porque la mediocridad no es un grado, es una >> | \'`'`/ | actitud" -- Jorge Wasenberg, 2015 >> | |'`'`| | (Mediocre is worse than good, but it is also worse than >> \/`'`'`'\/ bad, because mediocrity is not a grade, it is an attitude) >> =3D=3D=3D(((=3D=3D)))=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D+=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >> ! Dr.V=C3=ADctor Lua=C3=B1a, in silico chemist & prof. ! I hate the bure= aucracy >> ! Departamento de Qu=C3=ADmica F=C3=ADsica y Anal=C3=ADtica ! imposed by= companies to >> ! Universidad de Oviedo, 33006-Oviedo, Spain ! which I owe nothing: >> ! e-mail: victor(a)fluor.quimica.uniovi.es ! amazon, ResearchGATE an= d >> ! phone: +34-985-103491 fax: +34-985-103125 ! the like. >> +--------------------------------------------+ >> GroupPage : http://azufre.quimica.uniovi.es/ >> (being reworked) >> >> >> >> >> E-mail to subscribers: CHEMISTRY/a\ccl.net or use:>> >> E-mail to administrators: CHEMISTRY-REQUEST/a\ccl.net or use>> >> >> > > > -- > John McKelvey > 545 Legacy Pointe Dr > O'Fallon, MO 63376 > 636-294-5302 > jmmckel/a\gmail.com > > > --001a1146f0f85bb4b5051eb081f5 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I think what is meant is that if you represent the electro= n density correctly, the net atomic charges should be independent of the ba= sis set used.
Methods that do not satisfy this property (such as Mullik= en populations) are non-physical and should be discarded.
It is p= ossible to construct atomic population analysis methods in which the atomic= populations depend only on the electron and spin density distributions wit= h no explicit basis set dependence.
In this latter case, even an = experimentally measured electron distribution could be used as input withou= t requiring a "basis set" at all.

Sincer= ely,

Tom


<= br>


On Mon, Aug 31, 2015 at 11:06 PM, Dr. Robert Molt Jr. r.molt.chemical= .physics+/-gmail.com <= ;owner-chemist= ry],[ccl.net> wrote:
=20 =20 =20
Atomic charge models are not basis independent; see Chris Cramer's book, chapter 9, p.314. Some models give charges which are consistent with increasing basis set size, some are not, but all depend on the basis.

If you have anions, you cannot describe the density correctly without diffuse functions; this is a basis set dependence.
Dr. Robert Molt Jr.
r.=
molt.chemical.physics]-[gmail.com
On 08/31/2015 11:14 PM, John McKelvey jmmckel(a)gmail.com wrote:
Hello,

There is a paper from a group in Germany demonstrating essentially basis set independence of atomic charges....=C2=A0 Terrible to say that while I remember the paper, and that the method has been installed in ORCA for the next release, I will have to search for the paper...=C2=A0 just moved from Indiana to Missouri so things are in a bit of disarray.

Maybe someone has seen this paper?


John
=C2=A0


Sent to CCL by: =3D?iso-8859-1?Q?V=3DEDctor_Lua=3DF1a?=3D Cab= al [victor ~~ fluor.quimica.uniovi.es]
On Mon, Aug 31, 2015 at 04:22:51PM -0400, Jim Kress jimkress35-x-gmail.com wrote:
>
> Sent to CCL by: "Jim Kress" [jimkress35]-[gmail.com= ]
> Did you use an ECP for Plutonium and if so, was it properly represented in
> the AIM analysis?

Jim,

QTAIM should refer to the all electron density. However there have
been explorations of using ECP valence densities and they can work if
you do it carefully. You can either add the core contributions to the
valence density (it works) or be advise that your electron density is
not complete, so there are properties of the real QTAIM analysis that
can not work.

For instance, the basins and the topological partition of the full
electron density (rho) is not equivalent if you are using only the
valence component (val-rho).

However, if the basins are well defined there is no problem in
integrating the valence density within the full electron rho. The same
can be said for the analysis of spin components, and so on.
Using the critic2 code a lot of strange numerical experiments of
this kind can be easily performed. The code also has techniques to
fulfill the valence density with core components.

Read on critic2 in this ref.

A. Otero-de-la-Roza et al, Comput phys Commun 182 (2013) 2232--2248

An updated version of the code and manual can be found on

<http://azufre.quimica.uniovi.es= /software.html#critic2>
<http://schooner.chem.dal.ca/wiki/Critic2= >

I may look for old work published on this subject, if you are truly
interested.

Best regards,
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0V=C3=ADct= or Lua=C3=B1a
--
=C2=A0 =C2=A0 =C2=A0.=C2=A0 .=C2=A0 =C2=A0 "In science a= person can be convinced by a good argument.
=C2=A0 =C2=A0 / `' \=C2=A0 =C2=A0That is almost impossibl= e in politics or religion"
=C2=A0 =C2=A0/(o)(o)\=C2=A0 (Adapted from Carl Sagan)
=C2=A0 /`. \/ .'\=C2=A0 "Lo mediocre es peor que lo = bueno, pero tambi=C3=A9n es peor
=C2=A0/=C2=A0 =C2=A0'`'`=C2=A0 =C2=A0\ que lo malo, p= orque la mediocridad no es un grado, es una
=C2=A0|=C2=A0 \'`'`/=C2=A0 | actitud" -- Jorge W= asenberg, 2015
=C2=A0|=C2=A0 |'`'`|=C2=A0 | (Mediocre is worse than = good, but it is also worse than
=C2=A0 \/`'`'`'\/=C2=A0 bad, because mediocrity i= s not a grade, it is an attitude)
=3D=3D=3D(((=3D=3D)))=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D+=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
! Dr.V=C3=ADctor Lua=C3=B1a, in silico chemist & prof. ! = I hate the bureaucracy
! Departamento de Qu=C3=ADmica F=C3=ADsica y Anal=C3=ADtica != imposed by companies to
! Universidad de Oviedo, 33006-Oviedo, Spain ! which I owe nothing:
! e-mail:=C2=A0 =C2=A0victor(a)fluor.quimica= .uniovi.es=C2=A0 =C2=A0! amazon, ResearchGATE and
! phone: +34-985-103491=C2=A0 fax: +34-985-103125 ! the like.
+--------------------------------------------+
=C2=A0GroupPage : http://azufre.quimica.uniovi.es/=
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0(being rework= ed)



--
John McKelvey
545 Legacy Pointe Dr


--001a1146f0f85bb4b5051eb081f5--