From owner-chemistry@ccl.net Tue Oct 16 11:54:01 2018 From: "Henrique C. S. Junior henriquecsj!^!gmail.com" To: CCL Subject: CCL: Magnetic couplings using DFT in a spin frustrated system Message-Id: <-53511-181016114956-25345-8GxaJiPPjjIeih5KZfsSxQ++server.ccl.net> X-Original-From: "Henrique C. S. Junior" Content-Type: multipart/alternative; boundary="000000000000f7736005785a802d" Date: Tue, 16 Oct 2018 12:49:12 -0300 MIME-Version: 1.0 Sent to CCL by: "Henrique C. S. Junior" [henriquecsj/a\gmail.com] --000000000000f7736005785a802d Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Thanks for your kind reply, Nuno and David. To grasp the concept, I=E2=80=99ve decided to go to the basics and read the= classic book on Molecular Magnetism by Professor Olivier Kahn. On chapter 10.1 Kahn works to get the formula for the relative energies on Zero Field: See a print of the page here *S'* varies by an integer from *0* to 2Sa and for every *S'* value *S* varies by an integer from |S'-Sb| to S'+Sb My main interest is the chapter 10.1.1 Copper(II) trinuclear species where Kahn states that we have Sa =3D = Sb =3D =C2=BD and that the relative energies of the states can be deduced from equation 10.1.6 (the book says 10.6 but it was probably a typo). E(1/2,1) =3D 0 E(3/2,1) =3D -3J/2 E(1/2,0) =3D -J + J=E2=80=99 Substituting the values for S and S=E2=80=99 I=E2=80=99m failing to get the= same results of 0, -3J/2 and -J + J=E2=80=99 and I=E2=80=99m getting, instead, 0.625J - 1.0= J=E2=80=B2, -0.875J - 1.0J=E2=80=B2, =E2=88=920.375J. You can see how I=E2=80=99m working to get = these results here in this Jupyter Notebook . Maybe someone with more experience could guide me on how do I get the same results as the book? Thanks in advance On Mon, Oct 15, 2018 at 1:06 PM David Case david.case[*]rutgers.edu < owner-chemistry|-|ccl.net> wrote: > > Sent to CCL by: David Case [david.case-*-rutgers.edu] > On Sat, Oct 13, 2018, Henrique C. S. Junior henriquecsj() gmail.com wrote= : > > > I=E2=80=99m working with a copper trimeric system that have the > > classic triangular shape and experiences spin frustration. This is my > first > > time dealing with such system and, so far, from what I=E2=80=99m readin= g, I know > > that the spins resonate between =E2=86=91=E2=86=91=E2=86=91 =E2=86=94 = =E2=86=91=E2=86=93=E2=86=91 =E2=86=94 =E2=86=91=E2=86=91=E2=86=93 and that = the triangle > have > > couplings Jab, Jbc and Jca. > > > > My question is: how it is possible, using DFT, to obtain the three > magnetic > > couplings (Jab, Jbc, Jca)? I=E2=80=99m supposing that the strategy of b= reaking > the > > molecule in three dimers and calculating a broken-symmetry is not going > to > > work, right? > > > P.S.: I=E2=80=99m doing my calculations using the ORCA package. > > A pretty detailed description of the procedure, written by ORCA authors, > is in Patazis et al. Chem. Eur. J. 15:5108-5123 (2009). > > ....dave case > > > > -=3D This is automatically added to each message by the mailing script = =3D-> > > --=20 *Henrique C. S. Junior* --000000000000f7736005785a802d Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Thanks for your kind reply, Nuno and David.

To grasp the concept, I=E2=80=99ve decided to go to the basics and read the classic book on Mole= cular Magnetism by Professor Olivier Kahn. On chapter 10.1 Kahn works to get=20 the formula for the relative energies on Zero Field:

See a print of the page here

S' varies by an integer from 0<= /b> to 2Sa and for every S' value S varies by an integer from |S'-Sb| to S'+Sb My main interest=20 is the chapter 10.1.1 Copper(II) trinuclear species where Kahn states=20 that we have Sa =3D Sb =3D =C2=BD and that the relative energies of the sta= tes=20 can be deduced from equation 10.1.6 (the book says 10.6 but it was=20 probably a typo).

E(1/2,1) =
=3D 0
E(3/2,1) =3D -3J/2
E(1/2,0) =3D -J + J=E2=80=99

Substituting the values for S=20 and S=E2=80=99 I=E2=80=99m failing to get the same results of 0, -3J/2 and = -J + J=E2=80=99 and=20 I=E2=80=99m getting, instead, 0.625J - 1.0J=E2=80=B2, -0.875J - 1.0J=E2=80= =B2, =E2=88=920.375J. You can=20 see how I=E2=80=99m working to get these results here in this Jupyter Noteboo= k.

Maybe someone with more experience could gui= de me on how do I get the same results as the book?

Thanks in advance


On Mon, Oct 15,= 2018 at 1:06 PM David Case david.case[*]rut= gers.edu <owner-chemistry= |-|ccl.net> wrote:

Sent to CCL by: David Case [david.case-*-rutgers.edu]
On Sat, Oct 13, 2018, Henrique C. S. Junior henriquecsj() gmail.com wrote:

> I=E2=80=99m working with a copper trimeric system that have the
> classic triangular shape and experiences spin frustration. This is my = first
> time dealing with such system and, so far, from what I=E2=80=99m readi= ng, I know
> that the spins resonate between =E2=86=91=E2=86=91=E2=86=91 =E2=86=94 = =E2=86=91=E2=86=93=E2=86=91 =E2=86=94 =E2=86=91=E2=86=91=E2=86=93 and that = the triangle have
> couplings Jab, Jbc and Jca.
>
> My question is: how it is possible, using DFT, to obtain the three mag= netic
> couplings (Jab, Jbc, Jca)? I=E2=80=99m supposing that the strategy of = breaking the
> molecule in three dimers and calculating a broken-symmetry is not goin= g to
> work, right?

> P.S.: I=E2=80=99m doing my calculations using the ORCA package.

A pretty detailed description of the procedure, written by ORCA authors, is in Patazis et al. Chem. Eur. J. 15:5108-5123 (2009).

....dave case



-=3D This is automatically added to each message by the mailing script =3D-=
E-mail to subscribers: CHEMISTRY|-|ccl.net or use:
=C2=A0 =C2=A0 =C2=A0 http://www.ccl.net/cgi-bin/ccl/s= end_ccl_message

E-mail to administrators: CHEMISTRY-REQUEST|-|ccl.net or use
=C2=A0 =C2=A0 =C2=A0 http://www.ccl.net/cgi-bin/ccl/s= end_ccl_message
=C2=A0 =C2=A0 =C2=A0 http://www.ccl.net/chemistry/sub_un= sub.shtml

Before posting, check wait time at: http://www.ccl.net

Job: http://www.ccl.net/jobs
Conferences: http://server.ccl.net/chemist= ry/announcements/conferences/

Search Messages: http://www.ccl.net/chemistry/sear= chccl/index.shtml
=C2=A0 =C2=A0 =C2=A0 http://www.ccl.net/spammers.txt

RTFI: http://www.ccl.net/chemistry/aboutccl/ins= tructions/




--
Henrique C. S. Junior

--000000000000f7736005785a802d--