From owner-chemistry@ccl.net Wed Aug 6 00:09:01 2008 From: "kamarul pet kamarul_pet]-[yahoo.com" To: CCL Subject: CCL: methods Message-Id: <-37494-080805235930-11397-8jz0uwivPcI6bYvMDI+YOw###server.ccl.net> X-Original-From: "kamarul pet" Date: Tue, 5 Aug 2008 23:59:26 -0400 Sent to CCL by: "kamarul pet" [kamarul_pet^_^yahoo.com] Hi all, I just want to check my structure is wright or wrong. I doing molecular dynamics using Hyperchem (Amber parameter) in vacuo experiments. 1. get structure from CCDDC 2. delete water and add double bond 3. add hydrogen 4. do optimization for the structure 5. insert charge using AM1single point. Can someone confirm to me my methods is right or wrong? From owner-chemistry@ccl.net Wed Aug 6 01:00:01 2008 From: "Kamal Pet kamarul_pet],[yahoo.com" To: CCL Subject: CCL: method Message-Id: <-37495-080806004633-31588-PD+CGK0Bwh32DBNRKreSAA**server.ccl.net> X-Original-From: Kamal Pet Content-Type: multipart/alternative; boundary="0-1590461180-1217994713=:14400" Date: Tue, 5 Aug 2008 20:51:53 -0700 (PDT) MIME-Version: 1.0 Sent to CCL by: Kamal Pet [kamarul_pet]~[yahoo.com] --0-1590461180-1217994713=:14400 Content-Type: text/plain; charset=us-ascii Hi all, I just want to check my structure is wright or wrong. I doing molecular dynamics using Hyperchem (Amber parameter) in vacuo eksperiment. 1. get structure from CCDDC 2. delete water and add double bond 3. add hydrogen 4. do optimization for the structure 5. insert charge using AM1single point. Can someone confirm to me my methods is right or wrong? --0-1590461180-1217994713=:14400 Content-Type: text/html; charset=us-ascii

Hi all,

I just want to check my structure is wright or wrong. I doing molecular dynamics using Hyperchem (Amber parameter) in vacuo eksperiment.

1. get structure from CCDDC

2. delete water and add double bond

3. add hydrogen

4. do optimization for the structure

5. insert charge using AM1single point.

Can someone confirm to me my methods is right or wrong?

--0-1590461180-1217994713=:14400-- From owner-chemistry@ccl.net Wed Aug 6 09:30:01 2008 From: "errol lewars elewars+*+trentu.ca" To: CCL Subject: CCL: Ab initio on bridged rings Message-Id: <-37496-080805172001-32689-WS5oSwDEm5oVnQ30WBzhUw|server.ccl.net> X-Original-From: errol lewars Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii; format=flowed Date: Tue, 05 Aug 2008 16:25:25 -0400 MIME-Version: 1.0 Sent to CCL by: errol lewars [elewars||trentu.ca] 2008 August 05 Could you give us the structure (cartesians) of one (preferably the smallest) of your troublesome conmpounds)? E. Lewars ============= Simon Halstead shalstead . hit.edu.cn wrote: >Sent to CCL by: "Simon Halstead" [shalstead:hit.edu.cn] > >Dear all, > >I am trying to optimize some bridged (1-4) cyclohexane rings. I initially optimized them using sempiempirical methods. These calculations converged very rapidly. However, I then tried to optimize the resulting structures at a higher level of theory. These high level calculations have failed to converge, despite being run for a large number of steps. I have tried HF, MP2 and B3LYP with a variety of basis sets but nothing appears to converge. Visualizing the outputs of the failed calculations shows no problems with the structure. >Does anyone have any experience with structures like this or can anyone give me a suggestion of how best to optimize bridged rings? >I am using GAMESS if this makes any differnce. > >Thanks for your help, > >Simon Halstead> > > >