From owner-chemistry@ccl.net Mon Dec 15 02:16:01 2008 From: "Tsung-Wen Yen peter308]*[gmail.com" To: CCL Subject: CCL: scf non-convergence in deMon2k running on large-sized metallic cluster Message-Id: <-38300-081215021430-1457-++VW2ui4ZzaA+2eCZTbOow:_:server.ccl.net> X-Original-From: "Tsung-Wen Yen" Date: Mon, 15 Dec 2008 02:14:27 -0500 Sent to CCL by: "Tsung-Wen Yen" [peter308]![gmail.com] to ccl subscribers: Recently, i tested several metallic clusters with atom numbers in the range 20~40, say Ag38,Cu3Au22,Cu2Au19. These materials are transtition metals. The annoying part is the seld-consisting field in these cases were hardly to be converged.I follow several approaches which claim may be able to solve the problem but they seem useless, for ex: David Young in his book "Computational Chemistry" suggested to use : 1) Try a different initial guess: I used "Core Density" as suggested by deMon2k manual, do you recommend any other intial guess better than it? 2) Use smear and level-shifting during scf: I have used level-shifting once in a while, but actually i am not aware of the real meaning of these two options and which values are appropriate to use, could you share your experience with me? For example: does the value have relations to the fermi-level Mo's energy? Or how do i choose which value is corrrect and helpful on scf convergence? 3) Enhance grid accuracy : I have try it but no use. 4) Change the geometry: Haven't try yet. Could this make any improvement? 5) Use a smaller basis : Currently i am using the (RECP19|SD) basis set , which one is smaller than it? I dont have any ideas. 6)Turn off DIIS : tried before, no significant help. 7) Increase the SCF cycles : I use N=500 , I assume it's enough long. 8) Use Forced Convergence Method: Not available in deMon2k these are some method quoted from David Young' book. As a matter of fact, I randomly changed my options according to these suggestions both from books and also from deMon2k manuals, but it seemed very futile. I wonder if any who is experienced could share your knowledge with me and give some advices such as a Standing Operating Procedure(S.O.P) on fixing this kind of situation, especially dealing with large transition clusters? Actually, I am a bit lost now since no matter how i try i can't solve this problem. I am willing to provide any detailed datas ,for ex: the Mo's coefficient ,energy and other quantities as long as it will reveal some chance to overcome this problem. Appreciated for your help and kindness. P.S. the initial geometries of clusters were obtained by a emperical gupta potential Global Minima searching algorithm, it was proved to be very reliable at predicting the correct geometry at 0 kelvin. Best regards Tsung-Wen Yen From owner-chemistry@ccl.net Mon Dec 15 17:41:01 2008 From: "Anatoli Korkin a_korkin\a/yahoo.com" To: CCL Subject: CCL: share information adbout your favorite soft and web tutorials Message-Id: <-38301-081215173832-30816-ukTunfjnm+qrDsvLwUZNXA::server.ccl.net> X-Original-From: "Anatoli Korkin" Date: Mon, 15 Dec 2008 17:38:28 -0500 Sent to CCL by: "Anatoli Korkin" [a_korkin*yahoo.com] Dear CCLers, We are planning to update the links at the "software" and "education pages at ASDN: http://www.asdn.net/asdn/links/software.shtml and http://www.asdn.net/asdn/links/education.shtml Your advice/information about your favorite software and/or web based tutorials in the area of atomic scale (molecular, nano) science not listed at these pages will be kindly appreciated. Thank you for your consideration. Best regards, Anatoli Korkin From owner-chemistry@ccl.net Mon Dec 15 19:04:01 2008 From: "Oscar U Ojeda oscar.ojeda{=}chemail.tamu.edu" To: CCL Subject: CCL: Nitroethane crystal structure Message-Id: <-38302-081215184944-26931-qFAeJuu0oV0CroGtBJXKvQ-$-server.ccl.net> X-Original-From: "Oscar U Ojeda" Date: Mon, 15 Dec 2008 18:49:40 -0500 Sent to CCL by: "Oscar U Ojeda" [oscar.ojeda~~chemail.tamu.edu] Dear CCL peers; For some reason, the crystal structure of this solvent (EtNO2) seems to escape from traditional (ISI, CCSD, etc.) resource hits. I would appreciate any pointers. Cheers Oscar From owner-chemistry@ccl.net Mon Dec 15 21:16:00 2008 From: "Imranpk imranpkm_-_gmail.com" To: CCL Subject: CCL: share information adbout your favorite soft and web tutorials Message-Id: <-38303-081215210339-30573-er1nFeQgxQ3KBxsq40Lppg,,server.ccl.net> X-Original-From: Imranpk Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Date: Tue, 16 Dec 2008 07:38:42 +0530 MIME-Version: 1.0 Sent to CCL by: Imranpk [imranpkm:_:gmail.com] Gabedit, MoCalc and Zodiac are missing Anatoli Korkin a_korkina/yahoo.com wrote: > Sent to CCL by: "Anatoli Korkin" [a_korkin*yahoo.com] > Dear CCLers, > > We are planning to update the links at the "software" and "education pages at ASDN: > > http://www.asdn.net/asdn/links/software.shtml > > and > > http://www.asdn.net/asdn/links/education.shtml > > Your advice/information about your favorite software and/or web based tutorials in the area of atomic scale (molecular, nano) science not listed at these pages will be kindly appreciated. > > Thank you for your consideration. > > Best regards, > Anatoli Korkin> > > >