From owner-chemistry@ccl.net Wed Apr 22 13:18:00 2020 From: "Marcel Swart (GMail) marcel.swart(-)gmail.com" To: CCL Subject: CCL:G: pKa calculation by gaussian Message-Id: <-54029-200422033659-25581-OFAb50uxbyzldyYAvZsZ6g-,-server.ccl.net> X-Original-From: "Marcel Swart (GMail)" Content-Type: multipart/alternative; boundary="Apple-Mail=_E3CFBEA2-062E-46AD-A33A-B258FD79DD5F" Date: Wed, 22 Apr 2020 09:36:50 +0200 Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.14\)) Sent to CCL by: "Marcel Swart (GMail)" [marcel.swart]![gmail.com] --Apple-Mail=_E3CFBEA2-062E-46AD-A33A-B258FD79DD5F Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 And for further background, see this quite extensive page by Chris = Cramer, Don Truhlar and co-workers: https://comp.chem.umn.edu/solvation/ > On 21 Apr 2020, at 22:11, David Shobe shobedavid*|*gmail.com = wrote: >=20 > Mohammed-- >=20 > As the ions should be separated in aqueous solution, calculation of = the ammonium ion (and ammonia) should be enough.=20 >=20 > However, for good results, you need a good model of the solvent. I = think you'll need at least 4 explicit water molecules, one at each H = atom of the NH4+. >=20 > The pKa of ammonium is something you can look up in a table. The = interesting question is what level of theory, including solvent model, = gives the best results. >=20 > --David >=20 > On Wed, Apr 15, 2020, 4:09 PM Ibtesam Mohammed Desoky = girl51115..yahoo.com > wrote: >=20 > Sent to CCL by: "Ibtesam Mohammed Desoky" [girl51115]-[yahoo.com = ] >=20 >=20 > Dear CCLers, >=20 > How can I calculate pKa for ammonium iodide by gaussian16? >=20 > I would like to calculate pKa for ammonium iodide, do I have to put = iodide=20 > or just do calculations for ammonium using gaussian16 ?? >=20 > Best regards, > Ibtesam >=20 >=20 >=20 > -=3D This is automatically added to each message by the mailing script = =3D- >=20 >=20 >=20 > E-mail to subscribers: CHEMISTRY|a|ccl.net = or use:= >=20 > E-mail to administrators: CHEMISTRY-REQUEST|a|ccl.net = or use= >=20 >=20= >=20= >=20=20 > Conferences: = http://server.ccl.net/chemistry/announcements/conferences/ = >=20= >=20 >=20= >=20= >=20 >=20 Marcel Swart ICREA Research Professor at University of Girona Director of Institut de Qu=C3=ADmica Computacional i Cat=C3=A0lisi Univ. Girona, Campus Montilivi (Ci=C3=A8ncies) c/ M.A. Capmany 69 17003 Girona, Spain www.marcelswart.eu marcel.swart~~gmail.com vCard addressbook://www.marcelswart.eu/MSwart.vcf = --Apple-Mail=_E3CFBEA2-062E-46AD-A33A-B258FD79DD5F Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
And for further background, see this quite extensive page by = Chris Cramer, Don Truhlar and co-workers:
https://comp.chem.umn.edu/solvation/


On 21 Apr 2020, at 22:11, David Shobe shobedavid*|*gmail.com = <owner-chemistry~~ccl.net> wrote:

Mohammed--

As the ions = should be separated in aqueous solution, calculation of the ammonium ion = (and ammonia) should be enough. 

However, = for good results, you need a good model of the solvent. I think you'll = need at least 4 explicit water molecules, one at each H atom of the = NH4+.

The pKa of ammonium is something you can look up = in a table. The interesting question is what level of theory, including = solvent model, gives the best results.

--David

On Wed, Apr 15, 2020, 4:09 PM Ibtesam = Mohammed Desoky girl51115..yahoo.com <owner-chemistry|a|ccl.net> wrote:

Sent to CCL by: "Ibtesam Mohammed Desoky" [girl51115]-[yahoo.com]


Dear CCLers,

How can I calculate pKa for ammonium iodide by gaussian16?

 I would like to calculate pKa for ammonium iodide, do I have to = put iodide
or just do calculations for ammonium using gaussian16 ??

Best regards,
  Ibtesam



-=3D This is automatically added to each message by the mailing script = =3D-



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Marcel Swart
ICREA Research = Professor at University of Girona
Director of Institut de Qu=C3=ADmica Computacional = i Cat=C3=A0lisi

Univ. Girona, Campus Montilivi = (Ci=C3=A8ncies)
c/ M.A. = Capmany 69
17003 Girona, Spain

www.marcelswart.eu
marcel.swart~~gmail.com

vCard
addressbook://www.marcelswart.eu/MSwart.vcf

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