From owner-chemistry@ccl.net Sat Jan 26 12:20:01 2019 From: "Jens Spanget-Larsen spanget#ruc.dk" To: CCL Subject: CCL: SV: SV: Looking for a PPP parameter set Message-Id: <-53600-190126111220-17370-yrhtZP1z/pBBSa4AE+cWiA%server.ccl.net> X-Original-From: Jens Spanget-Larsen Content-Language: da-DK Content-Type: multipart/alternative; boundary="_000_A94E15A372E6194CA8719D62642F6744017304B870MBX2adrucdk_" Date: Sat, 26 Jan 2019 16:12:12 +0000 MIME-Version: 1.0 Sent to CCL by: Jens Spanget-Larsen [spanget~~ruc.dk] --_000_A94E15A372E6194CA8719D62642F6744017304B870MBX2adrucdk_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear Gustavo, in the 1970ies Josef Michl and his collaborators investigated application o= f the PPP-CI model to the spectra of conjugated systems, focussing on exten= ded CI schemes such as SECI-1 and SECI-2. You may find useful information i= n their work, see for example: J.W. Downing, J. Michl*, P. Jorgensen, E.W. Thulstrup, Theor. Chim. Acta 19= 74, 32, 203. You may also find something of interest in the development of the LCOAO mod= el, which may be considered as an extension of the PPP-CI model to include = all valence electrons: J. Spanget-Larsen, Theor. Chem. Acc. 1997, 98, 137-153. Yours, Jens >--< ------------------------------------------------------ JENS SPANGET-LARSEN Office: +45 4674 2710 Dept. of Science Fax: +45 4674 3011 Roskilde University Mobile: +45 2320 6246 P.O.Box 260 E-Mail: spanget() ruc.dk DK-4000 Roskilde, Denmark Web: thiele.ruc.dk/~spanget ------------------------------------------------------ ________________________________________ Fra: owner-chemistry+spanget=3D=3Druc.dk() ccl.net [owner-chemistry+spanget= =3D=3Druc.dk() ccl.net] på vegne af GUSTAVO LAUREANO COELHO DE MOURA gus= tavo.moura|ufpe.br [owner-chemistry() ccl.net] Sendt: 25. januar 2019 23:38 Til: Jens Spanget-Larsen Emne: CCL: SV: Looking for a PPP parameter set Sent to CCL by: GUSTAVO LAUREANO COELHO DE MOURA [gustavo.moura]~[ufpe.br] Dear CCL Community, Two weeks ago, I sent a message to the list where I inquired about paramete= rs for PPP excited state calculations of organic molecules. So far, I have received only one helpful advice from Jens Spanget-Larsen re= garding the choice of the two-center two-electron integral equation (Ohno v= ersus Mataga-Nishimoto). I am still looking for PPP parameters, both one- and two-center integral pa= rameters. I am particularly interested in distance dependent two-center one= -electron resonance integrals between first neighbor centers. In a first mo= ment, I would settle for calculating only conjugated hydrocarbons. Therefore, I would be grateful if someone could point for a reference where= I can find such a fully self-contained PPP parameter set. Thank you very much in advance. Sincerely yours, Gustavo L.C. Moura ----- Mensagem original ----- De: "GUSTAVO LAUREANO COELHO DE MOURA gustavo.moura ~ ufpe.br" Para: "Moura, Gustavo L.C. " Enviadas: S=E1bado, 12 de janeiro de 2019 20:14:40 Assunto: CCL: SV: Looking for a PPP parameter set Sent to CCL by: GUSTAVO LAUREANO COELHO DE MOURA [gustavo.moura|-|ufpe.br] Dear Jens, Thank you very much for your input. I have been employing a CI approach that includes more than single excitati= ons in the calculations and I have observed that, in agreement with your in= fo, I get better results with the OH equation. Regarding the resonance integrals, I have been using a parameter set that e= mploys a linear relationship between first neighbors bond lengths and beta.= I have no plans of going beyond first neighbors for the resonance integral= s. In the end, what I am searching is a fully self-contained PPP parameter set= . One that does not employ different parameters or equations from different= sources. Sincerely yours, Gustavo L.C. Moura ----- Mensagem original ----- De: "Jens Spanget-Larsen spanget^^ruc.dk" Para: "Moura, Gustavo L.C. " Enviadas: S=E1bado, 12 de janeiro de 2019 6:42:35 Assunto: CCL: SV: Looking for a PPP parameter set Dear Gustavo! Whether you use MN or OH two-center electron repulsion integrals does not d= epend so much on the other PPP parameters. The choice depends primarily on = the configuration interaction (CI) expansion. If the expansion is limited t= o singly excited configurations (CIS), the strongly screened MN integrals t= end to be adequate. But if you include doubly or higher excited configurati= ons, thereby explicitly introducing terms in electron correlation, the less= screened OH integrals are more appropriate. You want to include distance depending resonance integrals (beta's). Let me= just mention that if you include resonance integrals between 'non-bonded' = centers, thereby abandoning the tight-binding approximation, you break the = spirit of the PPP concept. Yours, Jens >--< ------------------------------------------------------ JENS SPANGET-LARSEN Office: +45 4674 2710 Dept. of Science Fax: +45 4674 3011 Roskilde University Mobile: +45 2320 6246 P.O.Box 260 Mail: spanget]|[ruc.dk DK-4000 Roskilde, Denmark Web: thiele.ruc.dk/~spanget ------------------------------------------------------ ________________________________________ Fra: owner-chemistry+spanget=3D=3Druc.dk]|[ccl.net [owner-chemistry+spanget= =3D=3Druc.dk]|[ccl.net] på vegne af Gustavo L.C. Moura gustavo.moura(0= )ufpe.br [owner-chemistry]|[ccl.net] Sendt: 12. januar 2019 01:19 Til: Jens Spanget-Larsen Emne: CCL: Looking for a PPP parameter set Sent to CCL by: "Gustavo L.C. Moura" [gustavo.moura^ufpe.br] Dear CCL Community, For the continuation of my studies on excited states of organic molecules, = I have been looking for a set of Pariser-Parr-Pople parameters. I have already searched on Google and, so far, have not found a PPP paramet= er set that suits my needs. My main problem is with the two-center part of the Hamiltonian. First, I fo= und out that the choice between the Ohno (OH) or the Mataga-Nishimoto (MN) = equations for gamma affect my results a lot. Therefore, I need a parameter = set where the choice between OH or MN equations has already been made. Seco= nd, I would like to have resonance integrals that depend on the distance be= tween the atoms (not a constant as I have found in some places). I will be very grateful if someone out there points me in the right directi= on. Sincerely yours, Gustavo L.C. Mourahttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www= .ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt--_000_A94= E15A372E6194CA8719D62642F674401374B5E80MBX2adrucdk_ Content-Type: text/html; charset=3D"iso-8859-1" Content-Transfer-Encoding: quoted-printable

Dear Gustavo!
  
Whether you use MN or OH two-center electron repulsion integrals does = not depend so much on the other PPP parameters. The choice depends primaril= y on the configuration interaction (CI) expansion. If the expansion is limi= ted to singly excited configurations (CIS), the strongly screened MN integrals tend to be adequate. But if you = include doubly or higher excited configurations, thereby explicitly introdu= cing terms in electron correlation, the less screened OH integrals are more= appropriate. 

You want to include distance depending resonance integrals (beta's). L= et me just mention that if you include resonance integrals between 'non-bon= ded' centers, thereby abandoning the tight-binding approximation, you break= the spirit of the PPP concept.

Yours, Jens >--<  

------------------------------------------------------
JENS SPANGET-LARSEN              Office:= +45 4674 2710
Dept. of Science                 Fa= x: +45 4674 3011
Roskilde University              Mobile:= +45 2320 6246
P.O.Box 260                   =    Mail: spanget]|[ruc.dk
DK-4000 Roskilde, Denmark  Web: thiele.ruc.dk/~spanget
------------------------------------------------------

________________________________________
Fra: owner-chemistry+spanget=3D=3Druc.dk]|[ccl.net [owner-chemistry+= ;spanget=3D=3Druc.dk]|[ccl.net] p&#229; vegne af Gustavo L.C. Moura gus= tavo.moura(0)ufpe.br [owner-chemistry]|[ccl.net]
Sendt: 12. januar 2019 01:19
Til: Jens Spanget-Larsen
Emne: CCL: Looking for a PPP parameter set

Sent to CCL by: "Gustavo L.C. Moura" [gustavo.moura^ufpe.br]
Dear CCL Community,
For the continuation of my studies on excited states of organic molecules, = I have been looking for a set of Pariser-Parr-Pople parameters.
I have already searched on Google and, so far, have not found a PPP paramet= er set that suits my needs.
My main problem is with the two-center part of the Hamiltonian. First, I fo= und out that the choice between the Ohno (OH) or the Mataga-Nishimoto (MN) = equations for gamma affect my results a lot. Therefore, I need a parameter = set where the choice between OH or MN equations has already been made. Second, I would like to have resona= nce integrals that depend on the distance between the atoms (not a constant= as I have found in some places).
I will be very grateful if someone out there points me in the right directi= on.
Sincerely yours,
Gustavo L.C. Moura



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Dear Gustavo,

in the 1970ies Josef Michl and his collaborators investigated application o= f the PPP-CI model to the spectra of conjugated systems, focussing on exten= ded CI schemes such as SECI-1 and SECI-2. You may find useful information i= n their work, see for example:

J.W. Downing, J. Michl*, P. Jorgensen, E.W. Thulstrup, Theor. Chim. Acta 19= 74, 32, 203.

You may also find something of interest in the development of the LCOAO mod= el, which may be considered as an extension of the PPP-CI model to inc= lude all valence electrons:

J. Spanget-Larsen, Theor. Chem. Acc. 1997, 98, 137-153.

Yours, Jens >--<

  ------------------------------------------------------
  JENS SPANGET-LARSEN        Office= :       +45 4674 2710
  Dept. of Science        &nbs= p;  Fax:          +45= 4674 3011
  Roskilde University        Mobile= :       +45 2320 6246
  P.O.Box 260         &nb= sp;      E-Mail:      spanget() ruc.dk
  DK-4000 Roskilde, Denmark  Web: thiele.ruc.dk/~spanget
  ------------------------------------------------------
________________________________________
Fra: owner-chemistry+spanget=3D=3Druc.dk() ccl.net [owner-chemistry+s= panget=3D=3Druc.dk() ccl.net] p&#229; vegne af GUSTAVO LAUREANO COELHO DE= MOURA gustavo.moura|ufpe.br [owner-chemistry() ccl.net]
Sendt: 25. januar 2019 23:38
Til: Jens Spanget-Larsen
Emne: CCL: SV: Looking for a PPP parameter set

Sent to CCL by: GUSTAVO LAUREANO COELHO DE MOURA [gustavo.moura]~[ufpe.br]<= br> Dear CCL Community,
Two weeks ago, I sent a message to the list where I inquired about paramete= rs for PPP excited state calculations of organic molecules.
So far, I have received only one helpful advice from Jens Spanget-Larsen re= garding the choice of the two-center two-electron integral equation (Ohno v= ersus Mataga-Nishimoto).
I am still looking for PPP parameters, both one- and two-center integral pa= rameters. I am particularly interested in distance dependent two-center one= -electron resonance integrals between first neighbor centers. In a first mo= ment, I would settle for calculating only conjugated hydrocarbons.
Therefore, I would be grateful if someone could point for a reference where= I can find such a fully self-contained PPP parameter set.
Thank you very much in advance.
Sincerely yours,
            &nb= sp;   Gustavo L.C. Moura

----- Mensagem original -----
De: "GUSTAVO LAUREANO COELHO DE MOURA gustavo.moura ~ ufpe.br" &l= t;owner-chemistry-,-ccl.net>
Para: "Moura, Gustavo L.C. " <gustavo.moura-,-ufpe.br>
Enviadas: S=E1bado, 12 de janeiro de 2019 20:14:40
Assunto: CCL: SV: Looking for a PPP parameter set

Sent to CCL by: GUSTAVO LAUREANO COELHO DE MOURA [gustavo.moura|-|ufpe.br]<= br> Dear Jens,
Thank you very much for your input.
I have been employing a CI approach that includes more than single excitati= ons in the calculations and I have observed that, in agreement with your in= fo, I get better results with the OH equation.
Regarding the resonance integrals, I have been using a parameter set that e= mploys a linear relationship between first neighbors bond lengths and beta.= I have no plans of going beyond first neighbors for the resonance integral= s.
In the end, what I am searching is a fully self-contained PPP parameter set= . One that does not employ different parameters or equations from different= sources.
Sincerely yours,
            &nb= sp;   Gustavo L.C. Moura



----- Mensagem original -----
De: "Jens Spanget-Larsen spanget^^ruc.dk" <owner-chemistry##cc= l.net>
Para: "Moura, Gustavo L.C. " <gustavo.moura##ufpe.br>
Enviadas: S=E1bado, 12 de janeiro de 2019 6:42:35
Assunto: CCL: SV: Looking for a PPP parameter set

Dear Gustavo!

Whether you use MN or OH two-center electron repulsion integrals does not d= epend so much on the other PPP parameters. The choice depends primarily on = the configuration interaction (CI) expansion. If the expansion is limited t= o singly excited configurations (CIS), the strongly screened MN integrals tend to be adequate. But if you = include doubly or higher excited configurations, thereby explicitly introdu= cing terms in electron correlation, the less screened OH integrals are more= appropriate.

You want to include distance depending resonance integrals (beta's). Let me= just mention that if you include resonance integrals between 'non-bonded' = centers, thereby abandoning the tight-binding approximation, you break the = spirit of the PPP concept.

Yours, Jens >--<

------------------------------------------------------
JENS SPANGET-LARSEN         &n= bsp;    Office: +45 4674 2710
Dept. of Science          = ;       Fax: +45 4674 3011
Roskilde University         &n= bsp;    Mobile: +45 2320 6246
P.O.Box 260          &nbs= p;           Mail: spange= t]|[ruc.dk
DK-4000 Roskilde, Denmark  Web: thiele.ruc.dk/~spanget
------------------------------------------------------

________________________________________
Fra: owner-chemistry+spanget=3D=3Druc.dk]|[ccl.net [owner-chemistry+= ;spanget=3D=3Druc.dk]|[ccl.net] p&#229; vegne af Gustavo L.C. Moura gus= tavo.moura(0)ufpe.br [owner-chemistry]|[ccl.net]
Sendt: 12. januar 2019 01:19
Til: Jens Spanget-Larsen
Emne: CCL: Looking for a PPP parameter set

Sent to CCL by: "Gustavo L.C. Moura" [gustavo.moura^ufpe.br]
Dear CCL Community,
For the continuation of my studies on excited states of organic molecules, = I have been looking for a set of Pariser-Parr-Pople parameters.
I have already searched on Google and, so far, have not found a PPP paramet= er set that suits my needs.
My main problem is with the two-center part of the Hamiltonian. First, I fo= und out that the choice between the Ohno (OH) or the Mataga-Nishimoto (MN) = equations for gamma affect my results a lot. Therefore, I need a parameter = set where the choice between OH or MN equations has already been made. Second, I would like to have resona= nce integrals that depend on the distance between the atoms (not a constant= as I have found in some places).
I will be very grateful if someone out there points me in the right directi= on.
Sincerely yours,
Gustavo L.C. Mourahttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www= .ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt--_000_A94= E15A372E6194CA8719D62642F674401374B5E80MBX2adrucdk_
Content-Type: text/html; charset=3D"iso-8859-1"
Content-Transfer-Encoding: quoted-printable

<html dir=3D"ltr">
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<font face=3D"Courier New" size=3D"2"><br><= br> <div>Dear Gustavo!</div>
<div>&nbsp;&nbsp;</div>
<div>Whether you use MN or OH two-center electron repulsion integrals= does not depend so much on the other PPP parameters. The choice depends pr= imarily on the configuration interaction (CI) expansion. If the expansion i= s limited to singly excited configurations
 (CIS), the strongly screened MN integrals tend to be adequate. But if= you include doubly or higher excited configurations, thereby explicitly in= troducing terms in electron correlation, the less screened OH integrals are= more appropriate.&nbsp;</div>
<div><br>
</div>
<div>You want to include distance depending resonance integrals (beta= 's). Let me just mention that if you include resonance integrals between 'n= on-bonded' centers, thereby abandoning the tight-binding approximation, you= break the spirit of the PPP concept.</div>
<div><br>
</div>
<div>Yours, Jens &gt;--&lt; &nbsp;</div>
<div><br>
</div>
------------------------------------------------------<br>
JENS SPANGET-LARSEN &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; = &nbsp;&nbsp; Office: &#43;45 4674 2710<br>
Dept. of Science &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &am= p;nbsp; &nbsp; &nbsp; Fax: &#43;45 4674 3011<br>
Roskilde University &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; = &nbsp;&nbsp; Mobile: &#43;45 2320 6246<br>
P.O.Box 260 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbs= p; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; Mail: spanget]|[ru= c.dk<br>
DK-4000 Roskilde, Denmark&nbsp; Web: thiele.ruc.dk/~spanget<br> ------------------------------------------------------<br>
<br>
________________________________________<br>
Fra: owner-chemistry&#43;spanget=3D=3Druc.dk]|[ccl.net [owner-chemistry= &#43;spanget=3D=3Druc.dk]|[ccl.net] p&amp;#229; vegne af Gustavo L.= C. Moura gustavo.moura(0)ufpe.br [owner-chemistry]|[ccl.net]<br>
Sendt: 12. januar 2019 01:19<br>
Til: Jens Spanget-Larsen<br>
Emne: CCL: Looking for a PPP parameter set<br>
<br>
Sent to CCL by: &quot;Gustavo L.C. Moura&quot; [gustavo.moura^ufpe.= br]<br>
Dear CCL Community,<br>
For the continuation of my studies on excited states of organic molecules, = I have been looking for a set of Pariser-Parr-Pople parameters.<br> I have already searched on Google and, so far, have not found a PPP paramet= er set that suits my needs.<br>
My main problem is with the two-center part of the Hamiltonian. First, I fo= und out that the choice between the Ohno (OH) or the Mataga-Nishimoto (MN) = equations for gamma affect my results a lot. Therefore, I need a parameter = set where the choice between OH
 or MN equations has already been made. Second, I would like to have r= esonance integrals that depend on the distance between the atoms (not a con= stant as I have found in some places).<br>
I will be very grateful if someone out there points me in the right directi= on.<br>
Sincerely yours,<br>
Gustavo L.C. Moura<br>
<br>
<br>
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