From owner-chemistry@ccl.net Sat Mar 2 05:30:01 2013 From: "Sergio Manzetti sergio.manzetti=gmx.com" To: CCL Subject: CCL: On Symmetry Message-Id: <-48359-130302052918-19778-MxLSiwNFRbfdn+O/mYfVwA(0)server.ccl.net> X-Original-From: "Sergio Manzetti" Content-Type: multipart/alternative; boundary="========GMXBoundary250441362220144925054" Date: Sat, 02 Mar 2013 11:29:04 +0100 MIME-Version: 1.0 Sent to CCL by: "Sergio Manzetti" [sergio.manzetti+/-gmx.com] --========GMXBoundary250441362220144925054 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit The subdivision of the three examples: O2 Benzene Cyclohexane could be best organized if O2 was assigned to a A.inf. group, instead of D.inf.. The A would stand for A-hedral, given that one needs really three atoms to conclude a dihedral. Sergio --========GMXBoundary250441362220144925054 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable The subd= ivision of the three examples:

O2
Benzene
Cyclohexane<= br />

could be best organized if O2 was assigned to a A.inf.&nbs= p; group, instead of D.inf.. The A would stand for A-hedral, given that one= needs really three atoms to conclude a dihedral.

Sergio<= /span> --========GMXBoundary250441362220144925054-- From owner-chemistry@ccl.net Sat Mar 2 09:22:00 2013 From: "Felipe Pineda pideca : hotmail.com" To: CCL Subject: CCL: On Symmetry Message-Id: <-48360-130302092102-13734-/XuwdWNfG2AtSUTC08/R8A() server.ccl.net> X-Original-From: Felipe Pineda Content-Type: multipart/alternative; boundary="_e58e66e7-7f30-457f-97bc-79f92ce39e41_" Date: Sat, 2 Mar 2013 15:20:56 +0100 MIME-Version: 1.0 Sent to CCL by: Felipe Pineda [pideca^-^hotmail.com] --_e58e66e7-7f30-457f-97bc-79f92ce39e41_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable it looks like u r reinventing the bike wikipedia is ur friend > From: owner-chemistry_+_ccl.net To: fpineda_+_uni-bonn.de Subject: CCL: On Symmetry Date: Sat=2C 2 Mar 2013 11:29:04 +0100 The subdivision of the three examples: O2 Benzene Cyclohexane could be best organized if O2 was assigned to a A.inf. group=2C instead of= D.inf.. The A would stand for A-hedral=2C given that one needs really thre= e atoms to conclude a dihedral. Sergio = --_e58e66e7-7f30-457f-97bc-79f92ce39e41_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
it looks like u r reinventing the bike

wikipedia is ur friend
From: o= wner-chemistry_+_ccl.net
To: fpineda_+_uni-bonn.de
Subject: CCL: On Symme= try
Date: Sat=2C 2 Mar 2013 11:29:04 +0100

The subdivision of the three e= xamples:

O2
Benzene
Cyclohexane


could be best organ= ized if O2 was assigned to a A.inf. =3B group=2C instead of D.inf.. The= A would stand for A-hedral=2C given that one needs really three atoms to c= onclude a dihedral.

Sergio
= --_e58e66e7-7f30-457f-97bc-79f92ce39e41_-- From owner-chemistry@ccl.net Sat Mar 2 09:56:00 2013 From: "Yi-Ping Tong typ2469[]126.com" To: CCL Subject: CCL: Question on EHMO program Message-Id: <-48361-130302023600-22253-uxLo9BYL0a9Amrfiao5mQA---server.ccl.net> X-Original-From: "Yi-Ping Tong" Date: Sat, 2 Mar 2013 02:35:59 -0500 Sent to CCL by: "Yi-Ping Tong" [typ2469]=[126.com] Dear, Doe,s anybodies could tell me about EHMO (extended huckel molecular orbital theory and its calculational program? Is it can calculate any molecular system? e.g. non-pi bond molecule, ethane. Where can I get this program? Thank you! From owner-chemistry@ccl.net Sat Mar 2 10:31:00 2013 From: "Sergio Manzetti sergio.manzetti-x-gmx.com" To: CCL Subject: CCL: Question on Symmetry Message-Id: <-48362-130302035945-27358-mxi/Wp1lVFRRLrYvvOKPhw,server.ccl.net> X-Original-From: "Sergio Manzetti" Content-Type: multipart/alternative; boundary="========GMXBoundary250411362214776943611" Date: Sat, 02 Mar 2013 09:59:36 +0100 MIME-Version: 1.0 Sent to CCL by: "Sergio Manzetti" [sergio.manzetti|,|gmx.com] --========GMXBoundary250411362214776943611 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Dear Harry, thank you for the clarifying answer. Your thoughts made me realize that identifying the shape of the molecule could be a fast approach in concluding differences in symmetry. However, I would though like to stress that benzene has a C6V symmetry, and perhaps that is the root of my concern in equalizing O2 with Cyclohexane, and alienating Cyclohexane from benzene. Yes benzene and cyclohexane have a enormous difference in structure, but O2 and cyclohexane have an even more larger difference. I would therefore presume that there should be an additional criteria to separate these 3 from one another in a sound way. For instance, only benzene and O2 have an inversion center. However, the inversion center applied in cyclohexane yields its mirror image, not its inverse. This should actually alienate cyclohexane from both O2 and Benzene "by miles". The infinite axis in O2 separates it yet from both benzene and cyclohexane, thus pushing cyclohexane closer to benzene in symmetry. But all three vary so much from one anther, that they should belong in fact to an own point group. Point group O2: infinite axis defines uniqueness Point group benzene: inversion center define uniqueness Point group cyclohexane: "Improper" inversion center defines uniqueness. Thanks Harry again, and all the best Sergio ----- Original Message ----- > From: HARRY STERN hstern16__mac.com Sent: 03/02/13 04:58 AM To: Manzetti, Sergio Subject: CCL: Question on Symmetry hi Sergio, clearly Jim didn't know the answer. Whenever someone expresses impatience with a question, it is always for that reason and means it is a good question. I didn't know either (it's been a while since I had group theory) but I found these pages very helpful http://en.wikipedia.org/wiki/Point_groups_in_three_dimensions http://www.chem.uky.edu/research/Grossman/stereo/pointgroups.HTML after reading those, I would say that the essential difference between the dihedral groups and the cyclic groups is that the former have additional rotational symmetry (in addition to the primary symmetry of rotation about an axis). The latter do not. There is a dihedral family of point groups, but within that family, there are many different groups (in fact, infinitely many). So in fact, cyclohexane and O2 have different point groups, as you would expect for such different-looking molecules. The point group for the chair conformation of cyclohexane is D3d, while homonuclear diatomics have the same point group as a cylinder, D inf h. Benzene has the point group D6h (just like a cylinder, but a six-fold axis of symmetry instead of an infinite-fold axis). Also - if you don't consider just a single conformation of cyclohexane, but think of the average structure on a longer timescale where it can interconvert between chair and boat, it has exactly the same symmetry as benzene. hope I've got all this right best - Harry On Mar 1, 2013, at 9:55 AM, Jim Kress ccl_nospam:+:http://kressworks.com < owner-chemistry*ccl.net > wrote: Have you actually read or studied any of the many references to Symmetry and the use of Symmetry in Chemistry? Try these: “Chemical Applications of Group Theory”, F. Albert Cotton, Wiley-Interscience http://www.amazon.com/Chemical-Applications-Group-Theory-Edition/dp/0471510947/ref=sr_1_1?ie=UTF8&qid=1362149201&sr=8-1&keywords=chemical+applications+of+group+theory “Group Theory and Chemistry” (Dover Books on Chemistry) by David M. Bishop http://www.amazon.com/Molecular-Symmetry-Group-Theory-Introduction/dp/0471489395/ref=sr_1_2?ie=UTF8&qid=1362149201&sr=8-2&keywords=chemical+applications+of+group+theory “Molecular Symmetry and Group Theory” by Robert L. Carter http://www.amazon.com/Molecular-Symmetry-Theory-Robert-Carter/dp/0471149551/ref=sr_1_5?ie=UTF8&qid=1362149201&sr=8-5&keywords=chemical+applications+of+group+theory In general: http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=chemical+applications+of+group+theory Or these: “Symmetry in Chemistry” (Dover Books on Chemistry) by Hans H. Jaffe and Milton Orchin http://www.amazon.com/Symmetry-Chemistry-Dover-Books/dp/0486421813/ref=sr_1_1?ie=UTF8&qid=1362149423&sr=8-1&keywords=Symmetry+in+Chemistry “Symmetry and Structure: Readable Group Theory for Chemists” by Sidney F. A. Kettle http://www.amazon.com/Symmetry-Structure-Readable-Theory-Chemists/dp/0470060409/ref=sr_1_3?ie=UTF8&qid=1362149423&sr=8-3&keywords=Symmetry+in+Chemistry In general: http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=Symmetry+in+Chemistry&rh=i%3Aaps%2Ck%3ASymmetry+in+Chemistry Or in Google Books: https://www.google.com/search?tbm=bks&hl=en&q=symmetry+in+chemistry Or just Google: https://www.google.com/search?q=symmetry%20in%20chemistry Jim Kress > From:owner-chemistry+ccl_nospam==http://kressworks.com ^_^http://ccl.net [mailto:owner-chemistry+ccl_nospam==http://kressworks.com ^_^http://ccl.net ] *On Behalf OfSergio Manzetti sergio.manzetti-*-http://gmx.com *Sent:*Friday, March 01, 2013 6:08 AM *To:*Kress, Jim *Subject:*CCL: Question on Symmetry Dear all, I have a question on the Dihedral group in the point group definitions. What is the main feature that differs the dihedral group (Dn) from the cyclic group (Cn) in terms of rules? The reason I ask is that, accordinng to what I have found, both oxygen (which is linear) and cyclohexane (which is cyclic, but not planar) belong to the Dihedral point group. Why is that? These molecules are so different, that one would prefer to put the cyclohexane in the same group with benzene for instance. Best wishes Sergio --========GMXBoundary250411362214776943611 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable Dear Har= ry, thank you for the clarifying answer. Your thoughts made me realize that= identifying the shape of the molecule could be a fast approach in concludi= ng differences in symmetry.

However, I would though like to stre= ss that benzene has a C6V symmetry, and perhaps that is the root of my conc= ern in equalizing O2 with Cyclohexane, and alienating Cyclohexane from benz= ene. Yes benzene and cyclohexane have a enormous difference in structure, b= ut O2 and cyclohexane have an even more larger difference. I would therefor= e presume that there should be an additional criteria to separate these 3 f= rom one another in a sound way.

For instance, only benzene and O= 2 have an inversion center. However, the inversion center applied in cycloh= exane yields its mirror image, not its inverse. This should actually aliena= te cyclohexane from both O2 and Benzene "by miles".

The infinite= axis in O2 separates it yet from both benzene and cyclohexane, thus pushin= g cyclohexane closer to benzene in symmetry. But all three vary so much fro= m one anther, that they should belong in fact to an own point group.
<= br />Point group O2: infinite axis defines uniqueness
Point group benz= ene: inversion center define uniqueness
Point group cyclohexane: "Impr= oper" inversion center defines uniqueness.

Thanks Harry again, a= nd all the best

Sergio
=C2=A0

=C2=A0

----- Original Me= ssage -----

From: HARRY STE= RN hstern16__mac.com

Sent: = 03/02/13 04:58 AM

<= span style=3D"font-family:Verdana">To: Manze= tti, Sergio

Subjec= t: CCL: Question on Symmetry

=C2=A0
hi Sergio, cl= early Jim didn't know the answer.  Whenever someone expresses impatien= ce with a question, it is always for that reason and means it is a good que= stion.  I didn't know either (it's been a while since I had group theo= ry) but I found these pages very helpful 
=C2=A0
<= a href=3D"http://en.wikipedia.org/wiki/Point_groups_in_three_dimensions">ht= tp://en.wikipedia.org/wiki/Point_groups_in_three_dimensions
<= a href=3D"http://www.chem.uky.edu/research/Grossman/stereo/pointgroups.HTML= ">http://www.chem.uky.edu/research/Grossman/stereo/pointgroups.HTML
=C2=A0
after reading those, I would say that the essential= difference between the dihedral groups and the cyclic groups is that the f= ormer have additional rotational symmetry (in addition to the primary symme= try of rotation about an axis).  The latter do not.
=C2=A0
There is a dihedral family of point groups, but within that family= , there are many different groups (in fact, infinitely many).  So in f= act, cyclohexane and O2 have different point groups, as you would expect fo= r such different-looking molecules.
The point group for the chair= conformation of cyclohexane is D3d, while homonuclear diatomics have the s= ame point group as a cylinder, D inf h.  Benzene has the point group D= 6h (just like a cylinder, but a six-fold axis of symmetry instead of an inf= inite-fold axis).  Also - if you don't consider just a single conforma= tion of cyclohexane, but think of the average structure on a longer timesca= le where it can interconvert between chair and boat, it has exactly the sam= e symmetry as benzene.
=C2=A0
hope I've got all this ri= ght
=C2=A0
best - Harry
=C2=A0
On Mar 1, 2013, at 9:55 AM, Jim Kress ccl_nospam:+:kressworks.com <owner-chemistry*ccl.net> wrote:
=C2=A0
Have you actually read or studied any of the many references= to Symmetry and the use of Symmetry in Chemistry?

=C2=A0

Try these:
=E2=80=9CChemical Applications of Group Theory=E2=80=9D, F. Alber= t Cotton, Wiley-Interscience

= =C2=A0

 
=E2=80= =9CGroup Theory and Chemistry=E2=80=9D (Dover Books on Chemistry) by David = M. Bishop

=C2=A0

http:/= /www.amazon.com/Molecular-Symmetry-Group-Theory-Introduction/dp/0471489395/= ref=3Dsr_1_2?ie=3DUTF8&qid=3D1362149201&sr=3D8-2&keywords=3Dche= mical+applications+of+group+theory

=C2=A0

 
=E2=80=9CMolecular Symme= try and Group Theory=E2=80=9D by Robert L. Carter

=C2=A0

http://www.amazon.com/Molecular-Symmetry-Theor= y-Robert-Carter/dp/0471149551/ref=3Dsr_1_5?ie=3DUTF8&qid=3D1362149201&a= mp;sr=3D8-5&keywords=3Dchemical+applications+of+group+theory=

=C2=A0

 
 
Or these= :

=C2=A0

 
=E2=80=9CSymmetry in Chemistry=E2=80=9D (Dover Books on Che= mistry) by Hans H. Jaffe and Milton Orchin

=C2=A0

 
=E2=80=9CSymmetry and Structure: Readable Group The= ory for Chemists=E2=80=9D by Sidney F. A. Kettle

=C2=A0

&nb= sp;
In general:=

=C2=A0

 
 
 
O= r just Google:

=C2=A0

 
 
 
Jim Kress

=C2=A0

 
 
From: owne= r-chemistry+ccl_nospam=3D=3Dkressworks.com^_^ccl.net=  [mailto:owner-chemis= try+ccl_nospam=3D=3Dkressworks.com^_^ccl.net] On Behalf Of Sergio Manzetti sergio.manzetti= -*-gmx.com
Sent: Friday, March 01, 2013 6:08 AM
To: Kress, Jim 
Subject: CCL: Question on Symmetry

=C2=A0

=C2=A0

Dear all, I h= ave a question on the Dihedral group in the point group definitions.
<= br />What is the main feature that differs the dihedral group (Dn) from the= cyclic group (Cn) in terms of rules?

The reason I ask is that, = accordinng to what I have found, both oxygen (which is linear) and cyclohex= ane (which is cyclic, but not planar) belong to the Dihedral point group.
Why is that? These molecules are so different, that one would pre= fer to put the cyclohexane in the same group with benzene for instance.

Best wishes

Sergio

=C2=A0

 --========GMXBoundary250411362214776943611-- From owner-chemistry@ccl.net Sat Mar 2 11:06:01 2013 From: "Sergio Manzetti sergio.manzetti _ gmx.com" To: CCL Subject: CCL: Question on Symmetry Message-Id: <-48363-130302040240-27667-WU7lPJ0vdk0WrVVZbBebtg|a|server.ccl.net> X-Original-From: "Sergio Manzetti" Content-Type: multipart/alternative; boundary="========GMXBoundary250411362214952566753" Date: Sat, 02 Mar 2013 10:02:32 +0100 MIME-Version: 1.0 Sent to CCL by: "Sergio Manzetti" [sergio.manzetti-x-gmx.com] --========GMXBoundary250411362214952566753 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit This kind of tone does not improve anything Jim. As also other have explained. Perhaps you can answer my recent question on the three molecules and show your extensive knowledge? Sergio ----- Original Message ----- > From: Jim Kress ccl_nospam:+:kressworks.com Sent: 03/01/13 03:55 PM To: Manzetti, Sergio Subject: CCL: Question on Symmetry Have you actually read or studied any of the many references to Symmetry and the use of Symmetry in Chemistry? Try these: “Chemical Applications of Group Theory”, F. Albert Cotton, Wiley-Interscience http://www.amazon.com/Chemical-Applications-Group-Theory-Edition/dp/0471510947/ref=sr_1_1?ie=UTF8&qid=1362149201&sr=8-1&keywords=chemical+applications+of+group+theory “Group Theory and Chemistry” (Dover Books on Chemistry) by David M. Bishop http://www.amazon.com/Molecular-Symmetry-Group-Theory-Introduction/dp/0471489395/ref=sr_1_2?ie=UTF8&qid=1362149201&sr=8-2&keywords=chemical+applications+of+group+theory “Molecular Symmetry and Group Theory” by Robert L. Carter http://www.amazon.com/Molecular-Symmetry-Theory-Robert-Carter/dp/0471149551/ref=sr_1_5?ie=UTF8&qid=1362149201&sr=8-5&keywords=chemical+applications+of+group+theory In general: http://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=chemical+applications+of+group+theory Or these: “Symmetry in Chemistry” (Dover Books on Chemistry) by Hans H. Jaffe and Milton Orchin http://www.amazon.com/Symmetry-Chemistry-Dover-Books/dp/0486421813/ref=sr_1_1?ie=UTF8&qid=1362149423&sr=8-1&keywords=Symmetry+in+Chemistry “Symmetry and Structure: Readable Group Theory for Chemists” by Sidney F. A. Kettle http://www.amazon.com/Symmetry-Structure-Readable-Theory-Chemists/dp/0470060409/ref=sr_1_3?ie=UTF8&qid=1362149423&sr=8-3&keywords=Symmetry+in+Chemistry In general: http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=Symmetry+in+Chemistry&rh=i%3Aaps%2Ck%3ASymmetry+in+Chemistry Or in Google Books: https://www.google.com/search?tbm=bks&hl=en&q=symmetry+in+chemistry Or just Google: https://www.google.com/search?q=symmetry%20in%20chemistry Jim Kress > From: owner-chemistry+ccl_nospam==kressworks.com^_^ccl.net [mailto:owner-chemistry+ccl_nospam==kressworks.com^_^ccl.net] *On Behalf Of *Sergio Manzetti sergio.manzetti-*-gmx.com *Sent:* Friday, March 01, 2013 6:08 AM *To:* Kress, Jim *Subject:* CCL: Question on Symmetry Dear all, I have a question on the Dihedral group in the point group definitions. What is the main feature that differs the dihedral group (Dn) from the cyclic group (Cn) in terms of rules? The reason I ask is that, accordinng to what I have found, both oxygen (which is linear) and cyclohexane (which is cyclic, but not planar) belong to the Dihedral point group. Why is that? These molecules are so different, that one would prefer to put the cyclohexane in the same group with benzene for instance. Best wishes Sergio --========GMXBoundary250411362214952566753 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable This kin= d of tone does not improve anything Jim. As also other have explained.

Perhaps you can answer my recent question on the three molecules and= show your extensive knowledge?

Sergio

=C2=A0

----- Origina= l Message -----

From: Jim K= ress ccl_nospam:+:kressworks.com

Sent: 03/01/13 03:55 PM

To: Manzetti, Sergio

Subject: CCL: Question on Symmetry

=C2=A0

Have you actually read or studied any of the = many references to Symmetry and the use of Symmetry in Chemistry?

=C2=A0

=C2=A0

=C2=A0

=C2=A0

=C2= =A0

Try these:
=E2=80=9CChemical Applications of Group Theory=E2=80=9D, F. Albert Cott= on, Wiley-Interscience

=C2= =A0

=C2=A0

http://www.amazon.com/Chemical-Applications-Group-Theory-Edition/dp/= 0471510947/ref=3Dsr_1_1?ie=3DUTF8&qid=3D1362149201&sr=3D8-1&key= words=3Dchemical+applications+of+group+theory

=C2=A0

= =C2=A0

=C2=A0

=C2=A0

=C2=A0

=E2=80=9CGroup Theory and Chemist= ry=E2=80=9D (Dover Books on Chemistry) by David M. Bishop

=C2=A0

=C2=A0

http://www.amazon.com/Molecul= ar-Symmetry-Group-Theory-Introduction/dp/0471489395/ref=3Dsr_1_2?ie=3DUTF8&= amp;qid=3D1362149201&sr=3D8-2&keywords=3Dchemical+applications+of+g= roup+theory

=C2=A0

=

=C2=A0

=C2= =A0

=C2=A0

=C2=A0

=E2=80=9CMolecular Symmetry and Group Theory=E2=80=9D by Robert L. Car= ter

=C2=A0

=C2=A0

http://www.ama= zon.com/Molecular-Symmetry-Theory-Robert-Carter/dp/0471149551/ref=3Dsr_1_5?= ie=3DUTF8&qid=3D1362149201&sr=3D8-5&keywords=3Dchemical+applica= tions+of+group+theory

= =C2=A0

=C2=A0

=C2=A0

=C2=A0

=C2=A0

In general:

http://www.amazon.com/s/ref=3Dnb_sb_noss_1?url= =3Dsearch-alias%3Daps&field-keywords=3Dchemical+applications+of+group+t= heory

=C2=A0

=C2=A0

=C2=A0

=C2=A0

=C2=A0

O= r these:

=C2=A0

=C2=A0

=C2=A0

=

=C2=A0

=C2=A0

= =E2=80=9CSymmetry in Chemistry=E2=80=9D (Dover Books on Chemistry) by Hans = H. Jaffe and Milton Orchin

=C2=A0

=C2=A0

http://www.amazon= .com/Symmetry-Chemistry-Dover-Books/dp/0486421813/ref=3Dsr_1_1?ie=3DUTF8&am= p;qid=3D1362149423&sr=3D8-1&keywords=3DSymmetry+in+Chemistry

=C2=A0

=C2=A0

=C2=A0

=C2=A0

=C2=A0

=E2=80=9CSymm= etry and Structure: Readable Group Theory for Chemists=E2=80=9D by Sidney F= . A. Kettle

=C2=A0

=C2=A0

http://www.amazon.c= om/Symmetry-Structure-Readable-Theory-Chemists/dp/0470060409/ref=3Dsr_1_3?i= e=3DUTF8&qid=3D1362149423&sr=3D8-3&keywords=3DSymmetry+in+Chemi= stry

=C2=A0

=C2=A0

=C2=A0

=

=C2=A0

=C2=A0

In= general:

=C2=A0

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=C2=A0

=C2=A0

<= a href=3D"http://www.amazon.com/s/ref=3Dnb_sb_noss?url=3Dsearch-alias%3Daps= &field-keywords=3DSymmetry+in+Chemistry&rh=3Di%3Aaps%2Ck%3ASymmetry= +in+Chemistry">http://www.amazon.com/s/ref=3Dnb_sb_noss?url=3Dsearch-alias%= 3Daps&field-keywords=3DSymmetry+in+Chemistry&rh=3Di%3Aaps%2Ck%3ASym= metry+in+Chemistry

=C2= =A0

=C2=A0

=C2=A0

=C2=A0

=C2=A0

Or in Google Books:

https://www.g= oogle.com/search?tbm=3Dbks&hl=3Den&q=3Dsymmetry+in+chemistry

=C2=A0

=C2=A0

=C2=A0

=C2=A0

=C2=A0

Or just Googl= e:

=C2=A0

=C2=A0

=C2=A0

=C2=A0

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https://ww= w.google.com/search?q=3Dsymmetry%20in%20chemistry

=C2=A0

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=

=C2=A0

Jim Kress

=C2=A0

=C2=A0

=C2=A0

=C2=A0

<= p style=3D"margin:0px; padding:0px;" >=C2=A0

=C2= =A0

=C2=A0

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<= b>From: owner-chemistry+ccl_nospam=3D=3D= kressworks.com^_^ccl.net [mailto:owner-chemistry+ccl_nospam=3D=3Dkressworks= .com^_^ccl.net] On Behalf Of Sergio Manzetti sergio.manzetti-*-gmx.c= om
Sent: Friday, March 01, 2013 6:08 AM
To: Kress, = Jim
Subject: CCL: Question on Symmetry

=C2=A0

= =C2=A0

=C2=A0

=C2=A0

=C2=A0<= /p>

Dear all, I have a question on the Di= hedral group in the point group definitions.

What is the main fe= ature that differs the dihedral group (Dn) from the cyclic group (Cn) in te= rms of rules?

The reason I ask is that, accordinng to what I hav= e found, both oxygen (which is linear) and cyclohexane (which is cyclic, bu= t not planar) belong to the Dihedral point group.

Why is that? T= hese molecules are so different, that one would prefer to put the cyclohexa= ne in the same group with benzene for instance.

Best wishes

Sergio

=C2=A0

=C2=A0

--========GMXBoundary250411362214952566753-- From owner-chemistry@ccl.net Sat Mar 2 11:41:00 2013 From: "CARLOS SIMMERLING carlos.simmerling|a|stonybrook.edu" To: CCL Subject: CCL: March 15 deadline for ACS COMP division awards for Fall 2013 Indianapo Message-Id: <-48364-130302080156-9823-0FoYjQPENpbYaMqwcRt87w!=!server.ccl.net> X-Original-From: "CARLOS SIMMERLING" Date: Sat, 2 Mar 2013 08:01:55 -0500 Sent to CCL by: "CARLOS SIMMERLING" [carlos.simmerling__stonybrook.edu] Applications are open for 3 types of awards from the ACS Division of Computers in Chemistry, to be awarded at the Fall 2013 national meeting in Indianapolis. The deadline is 5pm EDT Friday, March 15, 2013. 1) CCG Research Excellence award (graduate students) 2) OPENEYE Outstanding Junior Faculty Award (tenure-track Assistant Professors) 3) Peter Kollman Graduate Award in High Performance Computing CCG Research Excellence student travel award stipends are available for the Fall 2013 Indianapolis ACS National Meeting. The CCG Excellence Awards have been created to stimulate graduate student participation in ACS COMP Division activities (symposia and poster sessions) at ACS National Meetings. Those eligible for a CCG Excellence Award are graduate students in good standing who present work within the COMP program, either in oral or poster format. Winners receive $1,150 to offset their travel expenses, as well as a copy of CCG's MOE (Molecular Operating Environment) software with a one-year license. They are also honored during a ceremony at the COMP Division Poster Session. Up to 5 awardees will be chosen on the basis of the quality and significance of the research to be presented, as well as the strength of the supporting letter and other materials. All graduate students of the Americas (North, South or Central) are encouraged to submit applications. Awards will be given only to those individuals making presentations, not co-authors. There is a limit of one CCG award application per research lab. Previous winners are not eligible. To apply for an award for the ACS National Meeting in Indianapolis, IN, September 8-12, 2013, a title and extended abstract of the work (no more than 2 pages), a two page CV, a personal statement (no more than 1 page) and a letter of support from the research advisor should be sent as a SINGLE pdf or text file to carlos.simmerling ]|[ stonybrook.edu. Use the subject ACS CCG AWARD APPLICATION. You must use your last (family) name as the beginning of the file name. Letters of support can be sent separately from the other materials but must still arrive by the deadline and have the applicant's last name at the start of the file name. Applications that do not follow these rules cannot be considered The application deadline is 5pm EDT on Friday, March 15. Applicants will receive email confirmation of receipt of materials. If you do not receive confirmation by midnight March 19, please contact the organizer immediately by email (see below). In addition, you must submit your normal poster abstract to the "Chemical Computing Group Excellence Award" symposium on the ACS PACS system prior to the PACS deadline. Note that you MUST APPLY TWICE: email your complete application, and submit a standard abstract to PACS. Both must be submitted before their respective deadlines. Do not submit your PACS abstract to the standard poster session- it must be submitted for the CCG session or your application will not be considered. More information on awards offered by the ACS COMP division can be found on the web site at http://www.acscomp.org/Awards/index.html Carlos Simmerling Chair, ACS COMP Division Awards Committee Professor, Department of Chemistry Stony Brook University Stony Brook, NY 11794-3400 carlos.simmerling ]|[ stonybrook.edu OPENEYE Junior Faculty Award The ACS COMP OPENEYE Outstanding Junior Faculty Award program provides $1,000 to up to four outstanding tenure-track junior faculty members to present their work in COMP symposia at ACS National Meetings. The Awards are designed to assist new faculty members in gaining visibility within the COMP community. Award certificates and $1,000 prizes will be presented at the COMP Poster session. While special consideration will be given to Assistant Professors presenting work in the area of algorithm and methods development, applications for Outstanding Junior Faculty Awards are invited from all current tenure-track junior/untenured faculty (or equivalent positions in other institution types) who are members of ACS and the ACS Division of Computers in Chemistry. Postdoctoral researchers in transition to faculty appointments may also be considered. Selection criteria will include the novelty and importance of the work to be presented, CV of the applicant, as well as the level of Departmental support as indicated by the applicant's department Chair or Chair designee. To apply for an award for the ACS National Meeting in Indianapolis, IN, September 8-12, 2013, a title and extended abstract of the work (no more than 2 pages), a complete CV (including your ACS member number and confirmation that you are a member of the ACS COMP division) and the letter of departmental support should be sent as a SINGLE pdf or text file to carlos.simmerling ]|[ stonybrook.edu. Use the subject ACS OPENEYE AWARD APPLICATION. You must include your last (family) name at the start of the file name. Letters of support can be sent separately from the other materials but must still arrive by the deadline and have the applicant's last name at the start of the file name. Applications that do not follow these rules cannot be considered The application deadline is 5pm EDT on Friday, March 15. Applicants will receive email confirmation of receipt of materials. If you do not receive confirmation by midnight March 18, please contact the organizer immediately by email. In addition, you must submit your normal poster abstract to the "Outstanding Junior Faculty Award" symposium on the ACS PACS system prior to the PACS deadline. Note that you MUST APPLY TWICE: email your complete application, and submit a standard abstract to PACS. Both must be submitted before their respective deadlines. Do not submit your PACS abstract to the standard poster session- it must be submitted for the OPENEYE session or your application will not be considered. Note that the award application is for the poster session. If you want to also give an oral presentation, you must submit a separate abstract to PACS for an oral presentation in a relevant session, in addition to the poster abstract in the award section (note that acceptance into the oral sessions is not guaranteed). Use a somewhat different title for the talk and poster. More information on awards offered by the ACS COMP division can be found on the web site at http://www.acscomp.org/Awards/index.html Carlos Simmerling Chair, ACS COMP Division Awards Committee Professor, Department of Chemistry Stony Brook University Stony Brook, NY 11794-3400 carlos.simmerling ]|[ stonybrook.edu High Perfomance Computing Peter Kollman Graduate Award in High Performance Computing to be awarded at the Fall 2013 Indianapolis ACS National Meeting. The ACS Peter Kollman Graduate Award in High Performance Computing has been created to provide supercomputer resources to outstanding students in the early stages of their graduate career, particularly for projects that need high performance computing resources for their chemistry-related project. Those eligible for the award are graduate students in good standing who are carrying out research in the broadly defined area of computational chemistry. Winners (or their adviser, if necessary) will be the Principal Investigator of a new account on the kraken Cray XT5 supercomputer at the National Institute of Computational Sciences (NICS), with an allocation of computing time to support the project. For information about kraken, see http://www.nics.tennessee.edu/computing-resources/kraken. Allocations will be determined based on the requested amount and consideration of resource availability. Up to 2 awardees will be chosen on the basis of: the significance of the project plan, the potential impact on the project of obtaining additional supercomputer resources, the qualifications of the student, and the strength of the supporting letter and other materials. Projects with modest computational needs that can be performed on individual machines or small clusters are not likely to be competitive. Application requirements include a title and extended abstract of the work (no more than 1 page), a two page CV, a brief letter of support from the research advisor, and a 1-2 page detailed computational plan indicating: computational resources already available for the project, the types of calculations to be performed, experience of the applicant with high performance computing, availability of software, justification of number and length of runs, parallel scaling data, and an estimate of the total time needed. Submit the application to carlos.simmerling ]|[ stonybrook.edu as a SINGLE pdf or text file, and include your last name at the start of the file name. Use the subject ACS Kollman AWARD APPLICATION. There is a limit of one Kollman Award application per research lab (PI). Previous winners are not eligible. The application deadline is 5pm EDT on Friday, March 15. Applicants will receive email confirmation of receipt of materials. If you do not receive confirmation by midnight March 18, please contact the organizer immediately by email. Winners are encouraged but not required to present their work within the COMP program at the meeting, either in oral or poster format. If you want to present your work in an oral or poster presentation, you must also submit your abstract using the ACS PACS system, prior to the PACS deadline. Application for the supercomputing award does not constitute an application for a presentation. More information on awards offered by the ACS COMP division can be found on the web site at http://www.acscomp.org/Awards/index.html Carlos Simmerling Chair, ACS COMP Division Awards Committee Professor, Department of Chemistry Stony Brook University Stony Brook, NY 11794-3400 carlos.simmerling ]|[ stonybrook.edu From owner-chemistry@ccl.net Sat Mar 2 12:16:00 2013 From: "Sergio Manzetti sergio.manzetti\a/gmx.com" To: CCL Subject: CCL: On Symmetry Message-Id: <-48365-130302101721-11642-+pisV4fndezOlX5MJbayfg===server.ccl.net> X-Original-From: "Sergio Manzetti" Content-Type: multipart/alternative; boundary="========GMXBoundary13653136223743125470" Date: Sat, 02 Mar 2013 16:17:05 +0100 MIME-Version: 1.0 Sent to CCL by: "Sergio Manzetti" [sergio.manzetti]*[gmx.com] --========GMXBoundary13653136223743125470 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Yes, and I can probably sell you one too. But answer me on this Felipa Pineda Pideca, why are diatomic molecules belonging to a group called Dihedrals, when you need minimum of three atoms to define a dihedral? Sergio the bikemaker. ----- Original Message ----- > From: Felipe Pineda pideca : hotmail.com Sent: 03/02/13 03:20 PM To: Manzetti, Sergio Subject: CCL: On Symmetry it looks like u r reinventing the bike wikipedia is ur friend ----------------------------------------------------------------- > From: owner-chemistry^^^ccl.net To: fpineda^^^uni-bonn.de Subject: CCL: On Symmetry Date: Sat, 2 Mar 2013 11:29:04 +0100 The subdivision of the three examples: O2 Benzene Cyclohexane could be best organized if O2 was assigned to a A.inf. group, instead of D.inf.. The A would stand for A-hedral, given that one needs really three atoms to conclude a dihedral. Sergio --========GMXBoundary13653136223743125470 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable Yes, and= I can probably sell you one too.

But answer me on this Felipa P= ineda Pideca, why are diatomic molecules belonging to a group called Dihedr= als, when you need minimum of three atoms to define a dihedral?

= Sergio the bikemaker.

=C2=A0

----- Original Message -----

From: Felipe Pineda pideca : hotmail.co= m

Sent: 03/02/13 03:20 PM

To: Manzetti, Sergio -id#4gu= -

Subject: CCL: On Symmetry=

=C2=A0
it looks like u r reinventing the bike
wikipedia is ur friend
=C2=A0
=C2=A0
From: owner-chemistry^^^ccl.net<= br />To: fpineda^^^uni-bonn.de
Subject: CCL: On Symmetry
Date: Sa= t, 2 Mar 2013 11:29:04 +0100

The subdivision of the three examples:

O2
Benzene
Cyclohexane


could be best orga= nized if O2 was assigned to a A.inf.  group, instead of D.inf.. The A = would stand for A-hedral, given that one needs really three atoms to conclu= de a dihedral.

Sergio

=C2=A0

 --========GMXBoundary13653136223743125470-- From owner-chemistry@ccl.net Sat Mar 2 13:13:01 2013 From: "uekstrom%gmail.com uekstrom%gmail.com" To: CCL Subject: CCL: On Symmetry Message-Id: <-48366-130302130916-32763-Y2rcXl1SFYz+0EnSu9e9jw-x-server.ccl.net> X-Original-From: "uekstrom-$-gmail.com" Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=ISO-8859-1 Date: Sat, 2 Mar 2013 19:09:10 +0100 MIME-Version: 1.0 Sent to CCL by: "uekstrom|,|gmail.com" [uekstrom|,|gmail.com] > But answer me on this Felipa Pineda Pideca, why are diatomic molecules > belonging to a group called Dihedrals, when you need minimum of three atoms > to define a dihedral? Dihedral refers to the two planes of reflection that generate the group, not to any atoms. ~Ulf From owner-chemistry@ccl.net Sat Mar 2 14:22:00 2013 From: "Sergio Manzetti sergio.manzetti]_[gmx.com" To: CCL Subject: CCL: On Symmetry Message-Id: <-48367-130302141652-5316-jrePePAFSHMg24lxpNl12A[]server.ccl.net> X-Original-From: "Sergio Manzetti" Content-Type: multipart/alternative; boundary="========GMXBoundary250441362251799660123" Date: Sat, 02 Mar 2013 20:16:39 +0100 MIME-Version: 1.0 Sent to CCL by: "Sergio Manzetti" [sergio.manzetti|,|gmx.com] --========GMXBoundary250441362251799660123 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Thank you, but where does the word "hedral" give its function? Sergio ----- Original Message ----- > From: uekstrom%gmail.com uekstrom%gmail.com Sent: 03/02/13 07:09 PM To: Manzetti, Sergio Subject: CCL: On Symmetry Sent to CCL by: "uekstrom|,|gmail.com" [uekstrom|,|gmail.com] > But answer me on this Felipa Pineda Pideca, why are diatomic molecules > belonging to a group called Dihedrals, when you need minimum of three atoms > to define a dihedral? Dihedral refers to the two planes of reflection that generate the group, not to any atoms. ~ Ulfhttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt--========GMXBoundary250441362251799660123 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable Thank yo= u, but where does the word "hedral" give its function?

Sergio

=C2=A0

----- Original Message -----

From: uekstrom%gmail.com uekstrom%gmail.com

Sent: 03/02/13 07:09 PM

To: Manzetti, Sergio

Subject: CCL: On Symmetry

=C2= =A0
Sent to CCL by: "uekstrom|,|gmail.com" [uekstrom|,|gmail.co=
m]=20
> But answer me on this Felipa Pineda Pideca, why are diatomic molecules=
=20
> belonging to a group called Dihedrals, when you need minimum of three =
atoms=20
> to define a dihedral?=20

Dihedral refers to the two planes of reflection that generate the=20
group, not to any atoms.=20

~ Ulf=20



-=3D This is automatically added to each message by the mailing script =3D-=
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Subscribe/Unsubscribe:=20=20=20

Job: http://www.ccl.net/jobs=20=20=20=20=20
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=C2=A0

 --========GMXBoundary250441362251799660123-- From owner-chemistry@ccl.net Sat Mar 2 17:01:00 2013 From: "Salter-Duke, Brian James - brian.james.duke|*|gmail.com" To: CCL Subject: CCL: Question on EHMO program Message-Id: <-48368-130302152812-6069-CAFJLA+eUMrJ7Tt6ue1+cg:server.ccl.net> X-Original-From: "Salter-Duke, Brian James -" Content-Disposition: inline Content-Type: text/plain; charset=us-ascii Date: Sun, 3 Mar 2013 07:28:00 +1100 MIME-Version: 1.0 Sent to CCL by: "Salter-Duke, Brian James -" [brian.james.duke++gmail.com] On Sat, Mar 02, 2013 at 02:35:59AM -0500, Yi-Ping Tong typ2469[]126.com wrote: > > Sent to CCL by: "Yi-Ping Tong" [typ2469]=[126.com] > Dear, > Doe,s anybodies could tell me about EHMO (extended huckel molecular > orbital theory and its calculational program? Is it can calculate any > molecular system? e.g. non-pi bond molecule, ethane. Where can I get > this program? Thank you! I think YAEHMO (Yet Another Extended Molecular Orbital) Program is still available from the Hoffmann group. Let me know privately if you can not get it. Brian.> -- Brian Salter-Duke (Brian Duke) Brian.Salter-Duke]_[monash.edu Adjunct Associate Professor Monash Institute of Pharmaceutical Sciences Monash University Parkville Campus, VIC 3052, Australia From owner-chemistry@ccl.net Sat Mar 2 19:00:00 2013 From: "=?iso-8859-1?Q?S=E9rgio_Emanuel_Galembeck?= segalemb_._usp.br" To: CCL Subject: CCL: Question on EHMO program Message-Id: <-48369-130302185418-27007-WCoZlSTutogKldQ9mJKrVA[-]server.ccl.net> X-Original-From: =?iso-8859-1?Q?S=E9rgio_Emanuel_Galembeck?= Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=iso-8859-1 Date: Sat, 2 Mar 2013 20:53:56 -0300 Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\)) Sent to CCL by: =?iso-8859-1?Q?S=E9rgio_Emanuel_Galembeck?= [segalemb-.-usp.br] I suggest SAMOA, a easy to use software. http://www.primec.com/products/samoa/samoa.htm Best regards, Sergio Em 02/03/2013, s 17:28, "Salter-Duke, Brian James brian.james.duke|*|gmail.com" escreveu: > > Sent to CCL by: "Salter-Duke, Brian James " [brian.james.duke++gmail.com] > On Sat, Mar 02, 2013 at 02:35:59AM -0500, Yi-Ping Tong typ2469[]126.com wrote: >> >> Sent to CCL by: "Yi-Ping Tong" [typ2469]=[126.com] >> Dear, > >> Doe,s anybodies could tell me about EHMO (extended huckel molecular >> orbital theory and its calculational program? Is it can calculate any >> molecular system? e.g. non-pi bond molecule, ethane. Where can I get >> this program? Thank you! > > I think YAEHMO (Yet Another Extended Molecular Orbital) Program is still > available from the Hoffmann group. Let me know privately if you can not > get it. > > Brian.> > > -- > Brian Salter-Duke (Brian Duke) Brian.Salter-Duke[]monash.edu > Adjunct Associate Professor > Monash Institute of Pharmaceutical Sciences > Monash University Parkville Campus, VIC 3052, Australia> >