From owner-chemistry: at :ccl.net Tue Sep 6 11:08:49 2005 From: "CCL" To: CCL Subject: CCL: W:GTO and STO Message-Id: <-29074-050906110632-1720-2NbaQmdzjXHCm+8GjNpz2w]*[server.ccl.net> X-Original-From: Laurence Cuffe Content-disposition: inline Content-language: en Content-transfer-encoding: 7BIT Content-type: text/plain; charset=us-ascii Date: Tue, 06 Sep 2005 16:06:24 +0100 MIME-version: 1.0 Sent to CCL by: Laurence Cuffe [Laurence.Cuffe]*[ucd.ie] ----- Original Message ----- > From: CCL Date: Tuesday, September 6, 2005 2:33 pm Subject: CCL: W:GTO and STO > > Sent to CCL by: "Torsten Bruhn" [torsten.bruhn(!)mail.uni- > oldenburg.de]Hello, > > > can anyone tell me, why calculations with Gaussiantype-Orbitals are > faster than calculations with STO? Is there literature where this > is described in detail? The short answer is that calculating the overlap between two Gaussiantype -Orbitals can be done in closed form. That is given two GTO's A and B you can write an relatively simple algebraic expression for the size of the overlap between them. This is not possible with Slater type orbitals. While this is generally covered in most textbooks on computational chemistry, a google search on "GTO STO calculating overlap integrals" should get you some useful information. e.g http://www.mse.kth.se/~delin/sams_files/chapter7+8.pdf Jan Labanowski also has a good description of basis sets and how they're arrived at up on the web. All the best Dr Laurence Cuffe > > > > -= This is automatically added to each message by the mailing > script =- > To send e-mail to subscribers of CCL put the string CCL: on your > Subject: line> > Send your subscription/unsubscription requests to: CHEMISTRY- > REQUEST]*[ccl.net > HOME Page: http://www.ccl.net | Jobs Page: > http://www.ccl.net/jobs > > If your is mail bouncing from ccl.net domain due to spam filters, > please> -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- > +-+-+ > > > >