From owner-chemistry -A_T- ccl.net Tue Dec 20 22:59:01 2022 From: "Professor Doctor Vitaly Vitalievich Chaban vvchaban(0)gmail.com" To: CCL Subject: CCL: Adding many explicit water molecules to the model Message-Id: <-54834-221220165425-16394-/W6zokgh1+wZ8/FT8mSVJw**server.ccl.net> X-Original-From: Professor Doctor Vitaly Vitalievich Chaban Content-Type: multipart/alternative; boundary="0000000000002e776305f0497a2b" Date: Tue, 20 Dec 2022 23:53:40 +0200 MIME-Version: 1.0 Sent to CCL by: Professor Doctor Vitaly Vitalievich Chaban [vvchaban!^!gmail.com] --0000000000002e776305f0497a2b Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable ------------------------------------------ On Tue, Dec 20, 2022 at 9:50 PM Grigoriy Zhurko reg_zhurko_-_chemcraftprog.com wrote: > I need to compute the pKa values of some carbon acids and phenols, and it > is a common practice to add 1-3 explicit water molecules, bonded with pol= ar > groups of the studied molecule, to better take into account the specific > solvation effects (in addition to CPCM model). I tried to add many water > molecules (14) for better results =E2=80=93 see attached picture. The res= ults are > interesting. At one side, possibly very big error is produced by the > existence of many local minimums with different numbers of h bonds. How > these minimums should be named in paper =E2=80=93 maybe =E2=80=9Cconforma= tions=E2=80=9D, > =E2=80=9Cconfigurations=E2=80=9D, =E2=80=9Cgeometrical configurations=E2= =80=9D, =E2=80=9Clocal minimums=E2=80=9D? > Yes, local minima. Here is what will interest you https://scholar.google.com/citations?view_op=3Dview_citation&hl=3Den&user= =3DgT8ec74AAAAJ&sortby=3Dpubdate&citation_for_view=3DgT8ec74AAAAJ:vfT5ieZw1= WcC Sincerely yours, Prof. Vitaly V. Chaban (i10-index =3D 101, Hirsch =3D 33) Summary: https://sites.google.com/site/vvchaban Papers: https://scholar.google.com/citations?user=3DgT8ec74AAAAJ&hl=3Den ------------------------------------------ Then I found, that if the computation of different acids is performed with > same geometrical configurations of 5 h2o molecules bound to =E2=80=93COOH= , and with > same configurations for neutral molecule and anion, possibly the results > are quite good (a common correlation can be obtained for carbon acids and > phenols). So I want to publish these results; but I need to read more wor= ks > when this approach (adding many explicit water molecules) was used. Can y= ou > suggest such papers? > By the way, using my program Chemcraft is important for such jobs, becaus= e > the =E2=80=9CStructures merger=E2=80=9D utility in in allows one to trans= fer several H2O > molecules in same configuration from one acid to another. > Grigoriy Zhurko > https://chemcraftprog.com [image: Mailtrack] Sender notified by Mailtrack 20.12.22, 23:53:28 --0000000000002e776305f0497a2b Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


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On Tue, Dec 20, 2022 at 9:50 = PM Grigoriy Zhurko reg_zh= urko_-_chemcraftprog.com <owner-chemistry%ccl.net> wrote:
I need to compute the pKa values of some carbon aci= ds and phenols, and it is a common practice to add 1-3 explicit water molec= ules, bonded with polar groups of the studied molecule, to better take into= account the specific solvation effects (in addition to CPCM model). I trie= d to add many water molecules (14) for better results =E2=80=93 see attache= d picture. The results are interesting. At one side, possibly very big erro= r is produced by the existence of many local minimums with different number= s of h bonds. How these minimums should be named in paper =E2=80=93 maybe = =E2=80=9Cconformations=E2=80=9D, =E2=80=9Cconfigurations=E2=80=9D, =E2=80= =9Cgeometrical configurations=E2=80=9D, =E2=80=9Clocal minimums=E2=80=9D?


=C2=A0

Sincerely yours,=C2=A0
Prof. Vitaly V. Chaban (i10-index =3D 101, H= irsch =3D 33)
Summary:=C2=A0https://sites.google.com/site/vvchaban
Pape= rs:=C2=A0https://scholar.google.com/citations?user= =3DgT8ec74AAAAJ&hl=3Den
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<= blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-l= eft:1px solid rgb(204,204,204);padding-left:1ex"> Then I found, that if the computation of different acids is performed with = same geometrical configurations of 5 h2o molecules bound to =E2=80=93COOH, = and with same configurations for neutral molecule and anion, possibly the r= esults are quite good (a common correlation can be obtained for carbon acid= s and phenols). So I want to publish these results; but I need to read more= works when this approach (adding many explicit water molecules) was used. = Can you suggest such papers?
By the way, using my program Chemcraft is important for such jobs, because = the =E2=80=9CStructures merger=E2=80=9D utility in in allows one to transfe= r several H2O molecules in same configuration from one acid to another.
Grigoriy Zhurko
= https= ://chemcraftprog.com

=20
3D"Mailtrack" Sender notified by Mailtrack =20 20.12.22, 23:53:= 28 =20
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