From owner-chemistry@ccl.net Sat Jul 4 00:52:00 2015 From: "Abbey Philip abbeyphilip88(0)gmail.com" To: CCL Subject: CCL:G: Transition density Message-Id: <-51506-150703061354-18519-1iJvv1j9FPGvfoONVQZ6Zg=-=server.ccl.net> X-Original-From: Abbey Philip Content-Type: multipart/alternative; boundary=001a114e837ad5e08e0519f5cf5e Date: Fri, 3 Jul 2015 15:43:48 +0530 MIME-Version: 1.0 Sent to CCL by: Abbey Philip [abbeyphilip88 ~~ gmail.com] --001a114e837ad5e08e0519f5cf5e Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Dear all, Yes, I agree with Guegan Frederic that transition density cube could be generated in Gaussian using the cubegen utility. However I am not sure of such method for more than one molecule (10-12 molecules) in a cluster. If anybody can suggest a method for such calcualtions it would be helpful. The following paper gives the account of how the transition density cube generation can be done. J. Phys. Chem. B 1998, 102, 5378-5386 Regards, Abbey On Thu, Jul 2, 2015 at 1:09 AM, Guegan Frederic frederic.guegan/./ ens-lyon.fr wrote: > Dear all, > > Actually there is a way to access a transition density in gaussian. The > keyword "density=3Dcurrent", associated to "root=3Dn", allows you to acce= ss the > electron density for the nth excited state. Using cubegen (or gaussview), > you may then simply obtain the cubes for both the ground (density=3Dscf) = and > excited states, and compute the difference. You may also obtain it direct= ly > using ORCA (with the subprogram orca_plot). > > This density difference will on the other hand very likely involve all > your fragments, rather than one. I am not aware of any program that > decompose transition densities into fragment contributions, and as such I > usually use topological decompositions (in the spirit of AIM's theory, se= e > V. Tognetti, C. Morell, L. Joubert. J. Comput. Chem. 2015,36, 649=E2=80= =93659). > > Hope this helps ! > > Regards, > > Fred > > Le 2015-07-01 19:43, Xing Yin xiy726[]gmail.com a =C3=A9crit : > > Sent to CCL by: Xing Yin [xiy726[#]gmail.com] > I think the current version of Gaussian cannot calculate the transition d= ensity at all--or at least you cannot extract the information. I just asked= a similar question about a month ago. > http://www.ccl.net/cgi-bin/ccl/message-new?2015+06+01+003 > > Best wishes, > Xing > > On 06/29/2015 12:28 AM, Abbey Meprathu Philip abbeyphilip88(_)gmail.com w= rote: > > Sent to CCL by: "Abbey Meprathu Philip" [abbeyphilip88(0)gmail.com] Dear > all, I am trying to generate the transition densities for a cluster of > molecules (8-12 molecules) in a crystal using Gaussian software. I'm > planning to take the co-ordinates of the molecules in the crystal packing > and input them in Gaussian and use the following commands. > _________________________________________________________________________= __ > # td=3D(singlets,nstates=3D12) b3lyp/6-311++g(2d,2p) geom=3Dconnectivity > scf=3D(convergence=3D6,maxcycle=3D512) > _________________________________________________________________________= __ > Is this a correct method to calculate the transition density for more tha= n > one molecule. And will this lead to the transition density of entire > ensemble as whole or on the individual molecules of the crystal packing? > Regards, Abbey> > > > -=3D This is automatically added to each message by the mailing script = =3D-E-mail to subscribers: CHEMISTRY_+_ccl.net or use:> > E-mail to administrators: CHEMISTRY-REQUEST_+_ccl.net or usehttp://www.ccl.net/ch= emistry/sub_unsub.shtml > --001a114e837ad5e08e0519f5cf5e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

Dear all,<= span style=3D"font-size:12pt;font-family:Arial,sans-serif">

= =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0Yes, I agree with=C2=A0Guegan Frederic that tran= sition density cube could be generated in Gaussian using the=C2=A0cubegen= =C2=A0utility.=C2=A0However=C2=A0I am not sure of such method for more than= one molecule (10-12 molecules) in a cluster. If anybody can suggest a meth= od for such=C2=A0calcualtions=C2=A0it would be helpful.

= =C2=A0

= The following p= aper gives the account of how the transition density cube generation can be= done.

= J. Phys. Chem. = B 1998, 102, 5378-5386


Regards,

Abbey


On Thu, Jul 2, 2015 at 1:09 AM, Guegan Fre= deric frederic.guegan/./ens-lyon.fr <owner-chemistry_._ccl.net> wrote:

Dear all,

Actually there is a way to access a transition density in gaussian. The = keyword "density=3Dcurrent", associated to "root=3Dn", = allows you to access the electron density for the nth excited state. Using = cubegen (or gaussview), you may then simply obtain the cubes for both the g= round (density=3Dscf) and excited states, and compute the difference. You m= ay also obtain it directly using ORCA (with the subprogram orca_plot).

This density difference will on the other hand very likely involve all y= our fragments, rather than one. I am not aware of any program that decompos= e transition densities into fragment contributions, and as such I usually u= se topological decompositions (in the spirit of AIM's theory, see=C2=A0= V. Tognetti, C. Morell, L. Joubert. J. Comput. Chem. 2015,36, 649=E2=80=93= 659).

Hope this helps !

Regards,

Fred

Le 2015-07-01 19:43, Xing Yin xiy726[]gmail.com a =C3=A9crit=C2=A0:

Sent to CCL by: Xing Yin [xiy726[#]gmail.com]
I think the current version of Gaussian cannot calculate the transition den=
sity at all--or at least you cannot extract the information. I just asked a=
 similar question about a month ago.

http://www.ccl.net/cgi-bin/ccl/message-new?2015+06+01+003

Best wishes,
Xing

On 06/29/2015 12:28 AM, Abbey Meprathu Philip abbeyphilip88(_)gmail.com wrote:
Sent to CCL by: "Abbey Meprathu Philip" [= abbeyphilip88(0)gmail.com] Dear all, I am trying to generate the transition densities for a cluster= of molecules (8-12 molecules) in a crystal using Gaussian software. I'= m planning to take the co-ordinates of the molecules in the crystal packing= and input them in Gaussian and use the following commands. _______________= ____________________________________________________________ # td=3D(single= ts,nstates=3D12) b3lyp/6-311++g(2d,2p) geom=3Dconnectivity scf=3D(convergen= ce=3D6,maxcycle=3D512) ____________________________________________________= _______________________ Is this a correct method to calculate the transitio= n density for more than one molecule. And will this lead to the transition = density of entire ensemble as whole or on the individual molecules of the c= rystal packing? Regards, Abbey>
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