From owner-chemistry@ccl.net Sun Aug 31 13:53:00 2008 From: "Fu-Ming Ying fmying * gmail.com" To: CCL Subject: CCL: Pure vs. Cartesian Basis Functions Message-Id: <-37687-080829101538-28868-fP2ARbDalyuVwuscDc1M5Q!A!server.ccl.net> X-Original-From: Fu-Ming Ying Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8; format=flowed Date: Fri, 29 Aug 2008 15:00:39 +0200 MIME-Version: 1.0 Sent to CCL by: Fu-Ming Ying [fmying||gmail.com] hej I don' think the result will differ much for geometry optimization. But if you'd better use the same type during all the calculations. For example, if you use 5D in hf/3-21G, then I think it's better to use 5D in b3lyp/6-31++G(D,P) etc. gnli gnli,dicp.ac.cn wrote: > > *Dear CCLer,* > > *Please forgive me for my simple question.* > > *Is it necessary to keep the basis set to be Pure or Cartesian type > during all the calculate step in one system?* > > *For example, we optimize a molecule using “hf/3-21g hf/6-31g > b3lyp/6-31g b3lyp/6-31++g(d,p) b3lyp/aug-cc-pvdz” gradually, need we > define the Basis Functions all in 5D 7F or 6D 10F in the route section > consistently, or just using default? Is the difference serious? * > > *Thanks!* > > best wishes > Guanna Li > gnli]|[dicp.ac.cn > > > -- Fuming Ying Theoretical Chemistry, KTH AlbaNova University Center 106 91 Stockholm, Sweden