From owner-chemistry@ccl.net Wed May 18 00:08:01 2016 From: "Ayyaz Mahmood Ayyazcmc++gmail.com" To: CCL Subject: CCL:G: Need computational support Message-Id: <-52211-160518000706-16399-8p3/62L4ZFLtKBdTWfs0pA[*]server.ccl.net> X-Original-From: "Ayyaz Mahmood" Date: Wed, 18 May 2016 00:07:05 -0400 Sent to CCL by: "Ayyaz Mahmood" [Ayyazcmc*gmail.com] Dear Members, I need to run single-point CCSD(T) systems with Aug-cc-pVQZ basis set with ECP for four small systems (11 atoms) using Gaussian09. I have 16core machines but it is taking like forever to finish the calculations. We need to reply editor and there is a deadline. I would highly appreciate if someone could offer me computational support and run these calculations for me. I can send the input files. Sincerely, Ayyaz From owner-chemistry@ccl.net Wed May 18 09:32:00 2016 From: "Thomas Manz thomasamanz(!)gmail.com" To: CCL Subject: CCL: atomic population analysis Message-Id: <-52212-160518083011-31128-ed08AOL+UMvUd2a7tvtIdQ*|*server.ccl.net> X-Original-From: Thomas Manz Content-Type: multipart/alternative; boundary=94eb2c05bdf466604205331d04e8 Date: Wed, 18 May 2016 06:30:04 -0600 MIME-Version: 1.0 Sent to CCL by: Thomas Manz [thomasamanz(0)gmail.com] --94eb2c05bdf466604205331d04e8 Content-Type: text/plain; charset=UTF-8 Dear all, Recently, we had a vigorous discussion on this list about atomic population analysis methods (APAMs) that can be used to compute net atomic charges, atomic spin moments, bond orders, and other properties of atoms in materials. This is an important issue because: (1) The idea that materials are comprised of atoms is foundational to chemistry. It naturally follows that people want to quantify charge & spin transfer and bond orders between atoms in materials. (2) Until now none of the proposed APAMs has been demonstrated to be suitable for use as a default method in quantum chemistry programs independent of the basis set type used. By this I mean that the APAM should work well for a wide range of material types including molecules, solid surfaces, dense nonporous solids, porous solids, conducting metals, ions, magnetic materials, periodic structures, etc. Points (1) & (2) together highlight an important unmet need that has been present in computational chemistry for the past fifty years. (It is important to point out the progress made by quantum chemical topology, natural population & natural bond order analyses, and electrostatic potential (ESP) fitting methods. However, those methods have fundamental limitations for certain types of materials that prevent their use as default APAMs in quantum chemistry programs.) Although there is some flexibility in how to define net atomic charges, atomic spin moments, and bond orders, these quantities can provide useful information. I prefer the term "flexible" rather than "arbitrary", because I believe the performance of APAMs in comparison to experiments is important. One of the ways to address this issue of flexibility is through comparisons to spectroscopic trends and other experimental data. Most of the hypothetical APAM schemes that could be imagined do not correlate well with experiments across a wide range of materials. During our previous discussion, I promised to email this list when our article comparing computed net atomic charges to experimental data is published. The following two articles on this topic have now been published: 1.) T. A. Manz and N. Gabaldon Limas, "Introducing DDEC6 atomic population analysis: part 1. Charge partitioning theory and methodology," RSC Advances, 6 (2016) 47771-47801. ( http://dx.doi.org/10.1039/C6RA04656H ) 2.) N. Gabaldon Limas and T. A. Manz, "Introducing DDEC6 atomic population analysis: part 2. Computed results for a wide range of periodic and nonperiodic materials," RSC Advances, 6 (2016) 45727-45747. ( http://dx.doi.org/10.1039/C6RA05507A ) I believe these two articles make substantial progress in addressing the issues of how to compare APAMs to experimental data and of how to develop an APAM that is suitable for being used as a default method in quantum chemistry programs. If you are having difficulty accessing the full text of these articles because of journal subscription issues, you can access the full text by following links on this webpage: https://wordpress.nmsu.edu/tmanz/journal-articles/ Sincerely, Tom Manz --94eb2c05bdf466604205331d04e8 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Dear all,

Recently, we had a vigorous discussion on this li= st about atomic population analysis methods (APAMs) that can be used to com= pute net atomic charges, atomic spin moments, bond orders, and other proper= ties of atoms in materials.=C2=A0

This is an im= portant issue because:

(1) The idea that ma= terials are comprised of atoms is foundational to chemistry. It naturally f= ollows that people want to quantify charge & spin transfer and bond ord= ers between atoms in materials.

(2) Until now n= one of the proposed APAMs has been demonstrated to be suitable for use as a= default method in quantum chemistry programs independent of the basis set = type used. By this I mean that the APAM should work well for a wide range o= f material types including molecules, solid surfaces, dense nonporous solid= s, porous solids, conducting metals, ions, magnetic materials, periodic str= uctures, etc.

Points (1) & (2) together hig= hlight an important unmet need that has been present in computational chemi= stry for the past fifty years. (It is important to point out the progress m= ade by quantum chemical topology, natural population & natural bond ord= er analyses, and electrostatic potential (ESP) fitting methods. However, th= ose methods have fundamental limitations for certain types of materials tha= t prevent their use as default APAMs in quantum chemistry programs.)
<= div style=3D"font-size:12.8000001907349px">
Although there is some flexibility in how to define n= et atomic charges, atomic spin moments, and bond orders, these quantities c= an provide useful information. I prefer the term "flexible" rathe= r than "arbitrary", because I believe the performance of APAMs in= comparison to experiments is important. One of the ways to address this is= sue of flexibility is through comparisons to spectroscopic trends and other= experimental data. Most of the hypothetical APAM schemes that could be ima= gined do not correlate well with experiments across a wide range of materia= ls.=C2=A0

During our previous discussion, I pro= mised to email this list when our article comparing computed net atomic cha= rges to experimental data is published. The following two articles on this = topic have now been published:

1.) T. A. Manz and N. Gabaldon Limas, "Introducing DDEC6 atom= ic population analysis: part 1. Charge partitioning theory and methodology,= " RSC Advances, 6 (2016) 47771-47801. (=C2=A0http://dx.doi.org/10.1039/C6RA046= 56H=C2=A0)

2.) N. Gabaldon Limas and T. A. Manz, =C2=A0"Int= roducing DDEC6 atomic population analysis: part 2. Computed results for a w= ide range of periodic and nonperiodic materials," RSC Advances, 6 (201= 6) 45727-45747. (=C2=A0http://dx.doi.org/10.1039/C6RA05507A=C2=A0)

I bel= ieve these two articles make substantial progress in addressing the issues = of how to compare APAMs to experimental data and of how to develop an APAM = that is suitable for being used as a default method in quantum chemistry pr= ograms.

If you are having difficulty accessing = the full text of these articles because of journal subscription issues, you= can access the full text by following links on this webpage:

https://wordpress.nmsu.edu/tmanz/journal-articles/=

Sincerely,

To= m Manz
--94eb2c05bdf466604205331d04e8-- From owner-chemistry@ccl.net Wed May 18 13:37:01 2016 From: "janl:_:speakeasy.net" To: CCL Subject: CCL: CCL will be unattended until ~Jun 12, 2015 Message-Id: <-52213-160518133517-27113-AfekVybx4JLRcjO5vR2dCA,server.ccl.net> X-Original-From: janl###speakeasy.net Content-Disposition: inline Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Date: Wed, 18 May 2016 13:35:11 -0400 MIME-Version: 1.0 Sent to CCL by: janl ~~ speakeasy.net Dear CCL Members, I will be out of the country for 3 weeks starting tomorrow and there will be nobody to push the button. While I can try to login to the server and read my email, this obviously is not guaranteed. Expect delays or "no-action" until I return mid Jun (assuming that I have the same number of liftoffs and landings).Thank you for understanding. You've got what you paid for {:-(}. Jan -- Jan Labanowski CCL Manager jkl(_)ccl.net