From owner-chemistry@ccl.net Thu May 12 02:05:00 2011 From: "Arvydas.Tamulis..tfai.vu.lt" To: CCL Subject: CCL: micelle structure (PDB) files Message-Id: <-44618-110512020329-31557-qpCFFO4+pPwQSr7c/eeRQg===server.ccl.net> X-Original-From: Arvydas.Tamulis]=[tfai.vu.lt Content-Disposition: inline Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8; DelSp="Yes"; format="flowed" Date: Thu, 12 May 2011 09:03:11 +0300 MIME-Version: 1.0 Sent to CCL by: Arvydas.Tamulis]^[tfai.vu.lt Dear Andreas, Would you please compare moving figure 1 with figures 2 and 3 at the end of our article published in: at http://www.springerlink.com/content/7122n16869843314/fulltext.html You will see that in the figure ESM 1 exist only few hydrogen bonds that correspond to the experimental H-bonding length (dashed lines show these hydrogen bonds) because the geometry was optimized by semiempirical PM3 method. Figures ESM 2 and ESM 3 possess a lot of hydrogen bonds that correspond to the experimental H-bonding length because the geometries were reoptimized by using PBELYP/3-21 method. My experience comparing the Los Alamos artificial cells photosynthetic process spectra with our calculated spectra using TD DFT revPBE method with the 6-31G* basis set together with COSMO water solvent method in the ORCA program package differs only by 2-3 nanometers. The calculations of spectra of artificial cells with geometry optimized by semiempirical QM methods or MD programs gives up to 100 nm discrepancy with the experimental spectra results. With best regards, Arvydas http://www.itpa.lt/~tamulis/ "Andreas Klamt klamt**cosmologic.de" rašė: > > Sent to CCL by: Andreas Klamt [klamt[#]cosmologic.de] > Dear Arvydas, > > thank you very much for your reply, but from your paper I cannot > really see how you can conclude that MD results on micelles and > bio-membranes should be generally wrong. To our experience such > simulations give a reasonable picture of the composition, i.e. of > probability to find certain parts of surfactants and solvent > molecules in the layers of the micelle, and that is what we need to > know in order to calculate the free energy of solutes in such > micelles with the COSMOmic tool. We do not see major diferences in > the COSMOmic results depending on which specific MD results we are > using as input for the micelle composition. It seems that they are > rather comverged in that regard. > > Andreas > > Am 11.05.2011 06:26, schrieb Arvydas.Tamulis|tfai.vu.lt: >> >> Sent to CCL by: Arvydas.Tamulis{}tfai.vu.lt >> Dear Andreas, >> >> MD simulations give wrong results of micelle structure and even >> semiempirical QM methods are not sufficient. >> Please take a look to our DFT non local gradient investigations: >> A. Tamulis, M. Grigalavicius, „The Emergence and Evolution of Life >> in a “Fatty Acid World” Based on Quantum Mechanics”, Origins of >> Life and Evolution of Biospheres, 2011) vol. 41, pages 51-71. >> Electronical version of this article with moving micelles available >> at http://www.springerlink.com/content/7122n16869843314/fulltext.html >> >> Would you please to accept my proposal to cooperate in further >> investigations of micelles in the case if you have large computing >> possibilities. >> >> With best regards, >> Arvydas >> http://www.itpa.lt/~tamulis/ >> >> "Andreas Klamt klamt|-|cosmologic.de" rašė: >> >>> >>> Sent to CCL by: Andreas Klamt [klamt^^^cosmologic.de] >>> Dear CCLers, >>> >>> this time I like to post a question instead of commenting on other >>> peoples questions: >>> >>> Does anyone know a larger reservoir of micelle structure data >>> (most like stored in PDB format)? We would be interested in >>> collecting such structures, either based on experimental data or >>> on MD simulations. Maybe we could host a library of such files or >>> a library of links to such files on our web site. >>> >>> In the moment we are especially interested in SLES micelles. >>> >>> Thanks in advance >>> >>> Andreas >>> Klamthttp://www.ccl.net/chemistry/sub_unsub.shtmlConferences: >>> http://server.ccl.net/chemistry/announcements/conferences/http://www.ccl.net/chemistry/sub_unsub.shtml> >> Job: http://www.ccl.net/jobsConferences: >> http://server.ccl.net/chemistry/announcements/conferences/> >> >> > > > -- > PD. Dr. Andreas Klamt > CEO / Geschäftsführer > COSMOlogic GmbH& Co. KG > Burscheider Strasse 515 > D-51381 Leverkusen, Germany > > phone +49-2171-731681 > fax +49-2171-731689 > e-mail klamt{:}cosmologic.de > web www.cosmologic.de > > HRA 20653 Amtsgericht Koeln, GF: Dr. Andreas Klamt > Komplementaer: COSMOlogic Verwaltungs GmbH > HRB 49501 Amtsgericht Koeln, GF: Dr. Andreas Klamthttp://www.ccl.net/chemistry/sub_unsub.shtmlConferences: > http://server.ccl.net/chemistry/announcements/conferences/> > > From owner-chemistry@ccl.net Thu May 12 05:01:01 2011 From: "Pierre Archirel pierre.archirel###u-psud.fr" To: CCL Subject: CCL:G: basis set Message-Id: <-44619-110512045903-6498-RuevA3fbAOXR1V3c5MO9Hg]*[server.ccl.net> X-Original-From: "Pierre Archirel" Date: Thu, 12 May 2011 04:59:00 -0400 Sent to CCL by: "Pierre Archirel" [pierre.archirel|u-psud.fr] This is an answer to Arslan The SDD basis sets (from Stuttgart and Dresden) are smaller and much better than the Pople basis sets. They include core pseudos on every heavy atom (including CNO). If you are using gaussian you must add polarisation functions (for example a d shell with exponent .8 on CNO) with the extrabasis keyword. I have published a detailed comparison of the SDD and Pople basis sets in Tetrahedron 64 (2008) pp 1743-1752, about conformation analysis of a CNOH molecule with mass 300. From owner-chemistry@ccl.net Thu May 12 10:42:01 2011 From: "Arne Dieckmann adieckma*|*googlemail.com" To: CCL Subject: CCL: What's the appropriate method? Message-Id: <-44620-110512103938-5708-DwZQaq5Y+6ajVz7UfU567g**server.ccl.net> X-Original-From: "Arne Dieckmann" Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=us-ascii Date: 12 May 2011 16:39:26 +0200 Mime-Version: 1.0 (Apple Message framework v1084) Sent to CCL by: "Arne Dieckmann" [adieckma]*[googlemail.com] Dear all, I would like to optimize some structures containing nucleobases (and base-pairing) as well as peptide-bonds. Furthermore, potentials and barriers for some conformational changes and isomerizations should be determined. I would like to go beyond force fields as the molecules are small enough for e.g. semiempirical methods and use implicit solvation. What semiempirical method (AM1, PM3,...) - if any - would you recommend? Cheers, Arne From owner-chemistry@ccl.net Thu May 12 12:02:00 2011 From: "Sergio Emanuel Galembeck segalemb~~usp.br" To: CCL Subject: CCL: What's the appropriate method? Message-Id: <-44621-110512120037-8679-dQyEjt0ksE2GrixwJQJXqA*_*server.ccl.net> X-Original-From: Sergio Emanuel Galembeck Content-Disposition: inline Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes"; format="flowed" Date: Thu, 12 May 2011 13:00:25 -0300 MIME-Version: 1.0 Sent to CCL by: Sergio Emanuel Galembeck [segalemb-$-usp.br] Arne, I suggest PM6-DH2, present in MOPAC2000. Another option is RM1. Best regards, Sergio Citando "Arne Dieckmann adieckma*|*googlemail.com" : > > Sent to CCL by: "Arne Dieckmann" [adieckma]*[googlemail.com] > Dear all, > > I would like to optimize some structures containing nucleobases (and > base-pairing) as well as peptide-bonds. Furthermore, potentials and > barriers for some conformational changes and isomerizations should > be determined. I would like to go beyond force fields as the > molecules are small enough for e.g. semiempirical methods and use > implicit solvation. What semiempirical method (AM1, PM3,...) - if > any - would you recommend? > > > Cheers, > Arne> > > From owner-chemistry@ccl.net Thu May 12 12:49:00 2011 From: "=?ISO-8859-1?Q?Jo=E3o_Henriques?= joao.henriques.32353*gmail.com" To: CCL Subject: CCL: which basis set Message-Id: <-44622-110512124719-32363-3pq3f2Yh7sdBPp9bfPdpuw!^!server.ccl.net> X-Original-From: =?ISO-8859-1?Q?Jo=E3o_Henriques?= Content-Type: multipart/alternative; boundary=bcaec520e9fda2727e04a316f06b Date: Thu, 12 May 2011 09:47:08 -0700 MIME-Version: 1.0 Sent to CCL by: =?ISO-8859-1?Q?Jo=E3o_Henriques?= [joao.henriques.32353 : gmail.com] --bcaec520e9fda2727e04a316f06b Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Arslan, Well it depends on your final objective and how accurate you want the computation to be. This subject is non-black-box. However I would recommend 6-31G(d) (Valence Double Zeta + Polarization (Li-Ar)). It is relatively accurate and not that computationally expensive. Most publications in the field use this basis set for this type of calculation on CHNO elements. Regards, On Tue, May 10, 2011 at 7:06 AM, arslan ali arslanali1986{:}gmail.com < owner-chemistry]_[ccl.net> wrote: > hi, > > can anybody please tell me, which basis set in DFT will be more appropria= te > for geometry optimization of molecules of aprox 500 amu containing CHNO > elements only?? > > thanks in advance > > Arslan > --=20 Jo=E3o Henriques, MSc in Biochemistry Faculty of Science of the University of Lisbon Department of Chemistry and Biochemistry C8 Building, Room 8.5.47 Campo Grande, 1749-016 Lisbon, Portugal E-mail: joao.henriques.32353]_[gmail.com / jmhenriques]_[fc.ul.pt http://intheochem.fc.ul.pt/members/joaoh.html --bcaec520e9fda2727e04a316f06b Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Arslan,

Well it depends on your final objective and how accurate = you want the computation to be. This subject is non-black-box. However I wo= uld recommend 6-31G(d) (Valence Double Zeta + Polarization (Li-Ar)). It is = relatively accurate and not that computationally expensive. Most publicatio= ns in the field use this basis set for this type of calculation on CHNO ele= ments.

Regards,

On Tue, May 10, 2011 at 7:06= AM, arslan ali arslanali1986{:}gmail.com = <owner-chem= istry]_[ccl.net> wrote:
hi,

can an= ybody please tell me, which basis set in DFT will be more appropriate for g= eometry optimization of molecules of aprox 500 amu containing CHNO elements= only??

thanks in advance

Arslan



--
Jo=E3o Henriques= , MSc in Biochemistry
Faculty of Science of the University of Lisbon
= Department of Chemistry and Biochemistry
C8 Building, Room 8.5.47
Cam= po Grande, 1749-016 Lisbon, Portugal
E-mail: joao.henriques.32353]_[gmail.com /=A0jmhenriques]_[fc.ul.pt
--bcaec520e9fda2727e04a316f06b-- From owner-chemistry@ccl.net Thu May 12 13:24:00 2011 From: "Arne Dieckmann adieckma+*+googlemail.com" To: CCL Subject: CCL:G: What's the appropriate method? Message-Id: <-44623-110512124852-2478-V3CkL/1HyMQaUzGFjmGeMQ:server.ccl.net> X-Original-From: Arne Dieckmann Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=us-ascii Date: Thu, 12 May 2011 18:48:38 +0200 Mime-Version: 1.0 (Apple Message framework v1084) Sent to CCL by: Arne Dieckmann [adieckma++googlemail.com] Thanks, Sergio. Unfortunately, I will have to use Gaussian03 for the calculations. How about PM3MM then? On May 12, 2011, at 6:00 PM, Sergio Emanuel Galembeck segalemb~~usp.br wrote: > > Sent to CCL by: Sergio Emanuel Galembeck [segalemb-$-usp.br] > Arne, > > I suggest PM6-DH2, present in MOPAC2000. Another option is > RM1. > > Best regards, > > Sergio > > > > > Citando "Arne Dieckmann adieckma*|*googlemail.com" : > >> >> Sent to CCL by: "Arne Dieckmann" [adieckma]*[googlemail.com] >> Dear all, >> >> I would like to optimize some structures containing nucleobases (and base-pairing) as well as peptide-bonds. Furthermore, potentials and barriers for some conformational changes and isomerizations should be determined. I would like to go beyond force fields as the molecules are small enough for e.g. semiempirical methods and use implicit solvation. What semiempirical method (AM1, PM3,...) - if any - would you recommend? >> >> >> Cheers, >> Arnehttp://www.ccl.net/chemistry/sub_unsub.shtml> > Job: http://www.ccl.net/jobs> > From owner-chemistry@ccl.net Thu May 12 13:59:01 2011 From: "Mihaly Mezei Mihaly.Mezei()mssm.edu" To: CCL Subject: CCL: 0 start vs 1 start arrays Message-Id: <-44624-110512131208-21943-3m8AiSjCiSy584UCtvCixg|-|server.ccl.net> X-Original-From: Mihaly Mezei Content-disposition: inline Content-language: en Content-transfer-encoding: 7BIT Content-type: text/plain; charset=us-ascii Date: Thu, 12 May 2011 13:11:57 -0400 MIME-version: 1.0 Sent to CCL by: Mihaly Mezei [Mihaly.Mezei~~mssm.edu] Greetings, The advantage of starting indices from 0 instead of one is that when you have blocks of N numbers then to find out which block the index i is in, you have ib = i/N or ib = (i-1)/N+1 for zero-start list and 1-start list, resp. Similarly, to find out the place if the index i within its block, you have kb = mod(i,N) or kb = mod(i-1,N)+1 for zero-start list and 1-start list, resp. Mihaly Mezei Department of Structural and Chemical Biology, Mount Sinai School of Medicine Voice: (212) 659-5475 Fax: (212) 849-2456 WWW (MSSM home): http://www.mountsinai.org/Find%20A%20Faculty/profile.do?id=0000072500001497192632 WWW (Lab home - software, publications): http://inka.mssm.edu/~mezei WWW (Department): http://atlas.physbio.mssm.edu From owner-chemistry@ccl.net Thu May 12 14:58:00 2011 From: "Serge Lavilier m.o.m!A!live.fr" To: CCL Subject: CCL: installation of gar2ed Message-Id: <-44625-110512145642-29112-uewQPqof42KVb5rOou8ebA#,#server.ccl.net> X-Original-From: "Serge Lavilier" Date: Thu, 12 May 2011 14:56:39 -0400 Sent to CCL by: "Serge Lavilier" [m.o.m]=[live.fr] Hi, How to install the gar2ped software in ubuntu 9.04 Thanks From owner-chemistry@ccl.net Thu May 12 15:39:01 2011 From: "Gustavo Laureano Coelho de Moura gustavo.moura::ufpe.br" To: CCL Subject: CCL:G: What's the appropriate method? Message-Id: <-44626-110512134555-31777-GYEzD94zrQ6QUxQqPA3vZg===server.ccl.net> X-Original-From: Gustavo Laureano Coelho de Moura Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=utf-8 Date: Thu, 12 May 2011 14:44:53 -0300 (BRT) MIME-Version: 1.0 Sent to CCL by: Gustavo Laureano Coelho de Moura [gustavo.moura _ ufpe.br] Dear Arne, Please refer to the address http://rm1.sparkle.pro.br/rm1-software/gaussian09 to learn how to perform RM1 calculations using Gaussian. Sincerely yours, Gustavo L.C. Moura ----- Mensagem original ----- De: "Arne Dieckmann adieckma+*+googlemail.com" Para: "Gustavo L.C. Moura" Enviadas: Quinta-feira, 12 de Maio de 2011 13:48:38 Assunto: CCL:G: What's the appropriate method? Sent to CCL by: Arne Dieckmann [adieckma++googlemail.com] Thanks, Sergio. Unfortunately, I will have to use Gaussian03 for the calculations. How about PM3MM then? On May 12, 2011, at 6:00 PM, Sergio Emanuel Galembeck segalemb~~usp.br wrote: > > Sent to CCL by: Sergio Emanuel Galembeck [segalemb-$-usp.br] > Arne, > > I suggest PM6-DH2, present in MOPAC2000. Another option is > RM1. > > Best regards, > > Sergio > > > > > Citando "Arne Dieckmann adieckma*|*googlemail.com" : > >> >> Sent to CCL by: "Arne Dieckmann" [adieckma]*[googlemail.com] >> Dear all, >> >> I would like to optimize some structures containing nucleobases (and base-pairing) as well as peptide-bonds. Furthermore, potentials and barriers for some conformational changes and isomerizations should be determined. I would like to go beyond force fields as the molecules are small enough for e.g. semiempirical methods and use implicit solvation. What semiempirical method (AM1, PM3,...) - if any - would you recommend? >> >> >> Cheers, >> Arnehttp://www.ccl.net/chemistry/sub_unsub.shtml> > Job: http://www.ccl.net/jobshttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt From owner-chemistry@ccl.net Thu May 12 16:14:00 2011 From: "Ying Wang ywang1.:.ciw.edu" To: CCL Subject: CCL: software recommendation? Message-Id: <-44627-110512134514-28829-s21tyVqudIc83JyR6RYmCA*o*server.ccl.net> X-Original-From: "Ying Wang" Content-Language: en-us Content-Type: multipart/alternative; boundary="----=_NextPart_000_0028_01CC10AA.CB6AA370" Date: Thu, 12 May 2011 13:45:00 -0700 MIME-Version: 1.0 Sent to CCL by: "Ying Wang" [ywang1()ciw.edu] This is a multi-part message in MIME format. ------=_NextPart_000_0028_01CC10AA.CB6AA370 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Dear CCLers. I'm thinking about simulating high-temperature(up to ~1500 degC)-and-pressure(up to a few GPa) systems that consist of silicate mineral crystals/melts and water (up to 10 wt%). Interested properties include geometry, frequencies, etc. I've been working with QM simulation softwares on isolated molecules but have very limited experience on MD calculations. I wonder if anyone has experience and/or suggestions on the appropriate software package to use. Also, any comments and suggestions would be highly appreciated. Thanks in advance, Ying Wang ------=_NextPart_000_0028_01CC10AA.CB6AA370 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Dear = CCLers.

 

I’m thinking about simulating = high-temperature(up to ~1500 degC)-and-pressure(up to a few GPa) systems = that consist of silicate mineral crystals/melts and water (up to 10 = wt%). Interested properties include geometry, frequencies, etc. =

 

I’ve been working with QM simulation softwares = on isolated molecules but have very limited experience on MD = calculations. I wonder if anyone has experience and/or suggestions on = the appropriate software package to use. Also, any comments and = suggestions would be highly appreciated.

 

Thanks in = advance,

Ying Wang

------=_NextPart_000_0028_01CC10AA.CB6AA370-- From owner-chemistry@ccl.net Thu May 12 16:49:00 2011 From: "Jim Kress ccl_nospam:_:kressworks.com" To: CCL Subject: CCL: which basis set Message-Id: <-44628-110512151111-22264-bP80qyjeyaNQQXdqqsnzsg++server.ccl.net> X-Original-From: "Jim Kress" Content-language: en-us Content-Type: multipart/alternative; boundary="----=_NextPart_000_0013_01CC10B6.C47CFE80" Date: Thu, 12 May 2011 15:10:45 -0400 MIME-Version: 1.0 Sent to CCL by: "Jim Kress" [ccl_nospam(a)kressworks.com] This is a multi-part message in MIME format. ------=_NextPart_000_0013_01CC10B6.C47CFE80 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Frank Neese (of ORCA fame) is an excellent resource for this information = as is the documentation associated with ORCA. I=92d suggest you contact = him and get his opinion. =20 http://www.thch.uni-bonn.de/tc/orca/ =20 Jim Kress =20 =20 > From: owner-chemistry+ccl_nospam=3D=3Dkressworks.com{=}ccl.net [mailto:owner-chemistry+ccl_nospam=3D=3Dkressworks.com{=}ccl.net] On = Behalf Of Jo=E3o Henriques joao.henriques.32353*gmail.com Sent: Thursday, May 12, 2011 12:47 PM To: Kress, Jim Subject: CCL: which basis set =20 Hi Arslan, Well it depends on your final objective and how accurate you want the computation to be. This subject is non-black-box. However I would = recommend 6-31G(d) (Valence Double Zeta + Polarization (Li-Ar)). It is relatively accurate and not that computationally expensive. Most publications in = the field use this basis set for this type of calculation on CHNO elements. Regards, On Tue, May 10, 2011 at 7:06 AM, arslan ali arslanali1986{:}gmail.com > wrote: hi, can anybody please tell me, which basis set in DFT will be more = appropriate for geometry optimization of molecules of aprox 500 amu containing CHNO elements only?? thanks in advance Arslan --=20 Jo=E3o Henriques, MSc in Biochemistry Faculty of Science of the University of Lisbon Department of Chemistry and Biochemistry C8 Building, Room 8.5.47 Campo Grande, 1749-016 Lisbon, Portugal E-mail: joao.henriques.32353() gmail.com / jmhenriques() fc.ul.pt =20 http://intheochem.fc.ul.pt/members/joaoh.html =20 ------=_NextPart_000_0013_01CC10B6.C47CFE80 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Frank Neese (of ORCA fame) is an excellent resource for this = information as is the documentation associated with ORCA.=A0 I’d = suggest you contact him and get his opinion.

 

http://www.thch.uni-bonn.de/tc/orca/

 

Jim Kress

 

 

From:= = owner-chemistry+ccl_nospam=3D=3Dkressworks.com{=}ccl.net = [mailto:owner-chemistry+ccl_nospam=3D=3Dkressworks.com{=}ccl.net] On = Behalf Of Jo=E3o Henriques = joao.henriques.32353*gmail.com
Sent: Thursday, May 12, 2011 = 12:47 PM
To: Kress, Jim
Subject: CCL: which = basis set

 

Hi Arslan,

Well it depends on your = final objective and how accurate you want the computation to be. This = subject is non-black-box. However I would recommend 6-31G(d) (Valence = Double Zeta + Polarization (Li-Ar)). It is relatively accurate and not = that computationally expensive. Most publications in the field use this = basis set for this type of calculation on CHNO = elements.

Regards,

On = Tue, May 10, 2011 at 7:06 AM, arslan ali arslanali1986{:}gmail.com <owner-chemistry() = ccl.net> wrote:

hi,

can = anybody please tell me, which basis set in DFT will be more appropriate = for geometry optimization of molecules of aprox 500 amu containing CHNO = elements only??

thanks in advance

Arslan




--
Jo=E3o Henriques, MSc = in Biochemistry
Faculty of Science of the University of = Lisbon
Department of Chemistry and Biochemistry
C8 Building, Room = 8.5.47
Campo Grande, 1749-016 Lisbon, Portugal
E-mail: joao.henriques.32353() gmail.com / jmhenriques() = fc.ul.pt

 

------=_NextPart_000_0013_01CC10B6.C47CFE80-- From owner-chemistry@ccl.net Thu May 12 21:30:00 2011 From: "Guilherme Luis Cordeiro guilhermecord_-_gmail.com" To: CCL Subject: CCL: About solvation calculations Message-Id: <-44629-110512212709-22597-DX3AaX60eHsf+zB3Ps0h8A#server.ccl.net> X-Original-From: "Guilherme Luis Cordeiro" Date: Thu, 12 May 2011 21:27:05 -0400 Sent to CCL by: "Guilherme Luis Cordeiro" [guilhermecord[*]gmail.com] Dear members, I am kind of new in modeling systems in solution. I would appreciate if anyone could give me guidelines about using HB and micro solvation shells. What are they about? How can I start a calculation by using them? Can they provide better results than reaction field models of solvation? Thanks in advance, Guilherme Cordeiro. So Paulo State University/Brazil