Subject: Experiences in System Administration of the IBM RS/6000 SP

From: [email-masked] (Jeanne C. Butler)
Date: Tue, 23 Jul 1996 15:31:03 -0400

Cornell Theory Center Workshop

Experiences in System Adminstration of the IBM RS/6000 SP

Thursday, October 10 - Friday, October 11, 1996
Cornell Theory Center
Cornell University
Ithaca, NY

Registration deadline: Friday, September 6, 1996

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OVERVIEW
-------------
The Cornell Theory Center (CTC), a nationally funded high performance
computing center, is offering a 1.5 day workshop dealing with experiences in
system administration of the IBM SP. The workshop will consist mainly of a
series of panel sessions on different topics, given by representatives of
CTC and several other SP sites. Each panel session will feature short
presentations by panel members followed by time for discussion and questions
from the audience. IBM will give a presentation on and demonstration of
graphical tools being developed for system management. Ample time will be
provided for informal discussions.

CTC's SP, which consists of 512 RISC processors connected by a high
performance switch, is the largest of its kind in the world. Resource
scheduling is handled by EASY-LoadLeveler. Details may be found on the Web
at http://www.tc.cornell.edu/Resources/.

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PREREQUISITES
--------------------
This workshop is intended for system administrators who already have
experience in managing an SP system. Therefore, we will assume participants
are already familiar with the basics of managing an SP system, and have had
experience in doing so. Sessions will focus on sharing experiences, and will
not be tutorials. There will not be any hands-on sessions.

------------------------------------
REGISTRATION INFORMATION
------------------------------------
To register for this workshop, and for additional information, go to:
http://www.tc.cornell.edu/Edu/Upcoming/sysadm.html

From [email-masked] Jul 27 11:24:06 1996
Date: Wed, 10 Jul 1996 11:47:12 -0500
From: Irene Newhouse <[email-masked]>
To: [email-masked]
Subject: Re: CCL:M:Searching transition state with MOPAC; part2
Status: RO
Content-Length: 840

Try your latest structure in a frequency computation & see if there is indeed
1 & only 1 'negative' frequency [it's really imaginary, but is reported as
negative by the program].  I've found transition states to be very nonintuitive.
Not surprising, since so little experimental work can be done!  The 'obvious'
choices for TSs, I've found, are often  plain wrong!!!  If this is not indeed
a very reactant-like TS, & you still haven't located it, look at the literature
& see if you can find a similar computation somewhere.  Use that as a model,
no matter how strange it looks, & see where it gets you.  

For example, see Foresman & Frisch's book on using Gaussian for the Formal-
dehyde decomp/formation rxn from CO & H2.  I'd not have guessed that TS struc-
ture in a month of Sundays, yet that's what it is!

Good luck!
Irene Newhouse

From [email-masked] Jul 27 11:14:17 1996
Date: Wed, 10 Jul 96 9:22:32 METDST
From: Jose Ignacio Garcia <[email-masked]>
To: [email-masked]
Subject: SADDLE calculation
Status: RO
Content-Length: 1906

My guess for your problem is that the "terrible" result you get is mainly
due to the fact that you are trying to calculate an ion-molecule reaction
IN THE GAS PHASE. As ions are VERY unstable in the gas phase, its reactivity
can be also very different that that observed in solution, where the ion
is comfortably solvated. Thus, in general, in an isolated system calculation
as yours, an ion always will tend to be "solvated" by the neutral molecule,
through a polarisability mechanism, and will approach to its hydrogen atoms.
Often, this approach ends with a hydrogen abstraction reaction, as you 
observed. I have not experience with cation reactions, but this is exactly
what happens with the paradigmatic SN2 reaction between chloride ion and
methyl chloride. If one wants to correctly describe the SN2 attack, one
must be careful in designing the chloride approach trajectory.
Maybe the inclusion of solvation effects through a continuum model would
help to fix this problem.
I hope this helps you.
Best regards.

Jose I. Garcia

--
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Dr. Jose Ignacio Garcia-Laureiro                     Phone : 34-(9)76-762077
Departamento de Quimica Organica                                      761210
Instituto de Ciencia de Materiales de Aragon         Fax   : 34-(9)76-761159
C.S.I.C.-Universidad de Zaragoza                     e-mail: [email-masked]
E-50009 ZARAGOZA (SPAIN)                                     [email-masked]
                                                             [email-masked]
--------------------------------------------------------------------------------
"And all this science I don't understand it's just my job five days a week..."

                                               ELTON JOHN - Rocket man
--------------------------------------------------------------------------------

From [email-masked] Jul 27 11:16:34 1996
Date: Wed, 10 Jul 96 14:14:42 METDST
From: Jose Ignacio Garcia <[email-masked]>
To: [email-masked]
Subject: SADDLE calculation
Status: RO
Content-Length: 1491

Hello! It's me again. Have you tried to use an alternative method to SADDLE?
For instance, a reaction coordinate can be estimated by starting from the
product and breaking the C-C bond. As the C-C distance increases, the total
energy will change, and a maximum will probably appear. The structure
corresponding to this maximum can be then used as an starting point for a
TS or NLLSQ calculation.
By the way, I am still concerned with solvation. It is sure that in the
approach of the cation to the neutral molecule, an energy minimum
corresponding to an ion-molecule pair will be observed.
Best regards.

Jose I. Garcia
--
--------------------------------------------------------------------------------
Dr. Jose Ignacio Garcia-Laureiro                     Phone : 34-(9)76-762077
Departamento de Quimica Organica                                      761210
Instituto de Ciencia de Materiales de Aragon         Fax   : 34-(9)76-761159
C.S.I.C.-Universidad de Zaragoza                     e-mail: [email-masked]
E-50009 ZARAGOZA (SPAIN)                                     [email-masked]
                                                             [email-masked]
--------------------------------------------------------------------------------
"And all this science I don't understand it's just my job five days a week..."

                                               ELTON JOHN - Rocket man
--------------------------------------------------------------------------------