From owner-chemistry \\at// ccl.net Fri Feb 25 03:54:01 2011 From: "Eli Lam elizabeth.shlam_._gmail.com" To: CCL Subject: CCL:G: Gaussian03 optimisation problems Message-Id: <-44018-110225032651-7292-c4QkJcc6cBvL6QEQ0sYkBA=server.ccl.net> X-Original-From: "Eli Lam" Date: Fri, 25 Feb 2011 03:26:48 -0500 Sent to CCL by: "Eli Lam" [elizabeth.shlam^_^gmail.com] Dear Dave, I've tried to modify as advised and it works! And I have also tried to use the keyword opt(readfc) and opt(calcfc) and for some cases it works for the re-optimisation too. Thank you so much! Best regards, Eli > "Close, David M. CLOSED*o*mail.etsu.edu" wrote: > > Sent to CCL by: "Close, David M." [CLOSED+*+mail.etsu.edu] > Eli: > If you have a viewer you should animate the frequency that has the imaginary eigenvector. This represents a vibration in the direction that will lead to the true minimum. The trick is to > make a few changes in the X Y Z coordinates listed under the frequency and redo the calculation. Some trial and error may be needed, but it is not too difficult to displace the vibration off of the local minima and get it to move towards the true minima. Try this. If you don't succeed, send me the X Y Z coordinates and I will give it a try. > Regards, Dave Close. > > > -----Original Message----- > > From: owner-chemistry+closed==etsu.edu * ccl.net [mailto:owner-chemistry+closed==etsu.edu * ccl.net] On Behalf Of Eli Lam elizabeth.shlam!A!gmail.com > Sent: Saturday, February 19, 2011 8:27 PM > To: Close, David M. > Subject: CCL: Gaussian03 optimisation problems > > > Sent to CCL by: "Eli Lam" [elizabeth.shlam() gmail.com] > Hi, > > Recently when I do optimisation of a organometallic molecules, I've found an imaginary frequency in > the optimized structure, I know it would mean that the structure is not a minima in the PES. But how > should I optimise again to find the true minimum? Thanks! > > Elihttp://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://www.ccl.net/chemistry/sub_unsub.shtmlhttp://www.ccl.net/spammers.txt >