From owner-chemistry $#at#$ ccl.net Mon Jul 13 14:30:00 2009
From: "Jose Alberto Fernandes jafernandes{:}ua.pt" <owner-chemistry---server.ccl.net>
To: CCL
Subject: CCL:G: ONIOM Optimization
Message-Id: <-39768-090713142817-8648-52gVL7VscTzArpZ7vH4KCw---server.ccl.net>
X-Original-From: "Jose Alberto Fernandes" <jafernandes{:}ua.pt>
Date: Mon, 13 Jul 2009 14:28:13 -0400


Sent to CCL by: "Jose Alberto Fernandes" [jafernandes-,-ua.pt]
Hello Ajanta

That problems happens many times with me, and some times it is almost impossible to solve. Well, you have already tried to start with other structure. Let's try these approaches:
*Do not use guess=check
*Try to put the medium structure of the two structures corresponding to the two energies you have got. 
*Try to reduce the step in the optimization by adding opt(maxstep=1) in the input

Good luck

Jose



> "Ajanta Deka ajanta---tezu.ernet.in"  wrote:
> 
> Sent to CCL by: "Ajanta  Deka" [ajanta*tezu.ernet.in]
> Dear All,
> 
> I am trying to do an optimzation using ONIOM method (Gaussian 03)for
> faujasite zeolite. For the QM part I am using uB3LYP/6-31g(d,p) and
> uB3LYP/LanL2dz and UFF for the MM part. I observe something strange in the
> output. When I look at the energy values in the subsequent steps of
> optimization, this is what I find
> 
> SCF Done:  E(UB+HF-LYP) =  -2190.15693744     A.U. after   24 cycles
> SCF Done:  E(UB+HF-LYP) =  -2190.15700719     A.U. after   24 cycles
> SCF Done:  E(UB+HF-LYP) =  -2190.15693744     A.U. after   24 cycles
> SCF Done:  E(UB+HF-LYP) =  -2190.15700718     A.U. after   24 cycles
> SCF Done:  E(UB+HF-LYP) =  -2190.15693745     A.U. after   24 cycles
> SCF Done:  E(UB+HF-LYP) =  -2190.15700721     A.U. after   24 cycles
> SCF Done:  E(UB+HF-LYP) =  -2190.15693745     A.U. after   24 cycles
> SCF Done:  E(UB+HF-LYP) =  -2190.15700720     A.U. after   24 cycles
> SCF Done:  E(UB+HF-LYP) =  -2190.15693744     A.U. after   24 cycles
> SCF Done:  E(UB+HF-LYP) =  -2190.15700718     A.U. after   24 cycles
> 
> Thus, the energy is approaching two different values.
> Ultimately, the job fails with the following messaqe
> 
> Error termination request processed by link 9999.
> Error termination via Lnk1e in /home/ramesh/g03/l9999.exe at Sat Jul 11
> 18:01:11 2009
> Job cpu time:  6 days 21 hours 53 minutes  6.0 seconds.
> File lengths (MBytes):  RWF=    100 Int=      0 D2E=      0 Chk=     20
> Scr=      1
> 
> I have tried by changing the initial geometry slightly, but I get the same
> result. I have successfully got the optimized geometry for a similiar
> system (with slightly different charge). I do not know how to overcome
> this error. Please help me.
> 
> with warm regards,
> Ajanta Deka
> 
>