# Seminar Reminder

cobb
Date: Thu, 22 Apr 93 09:36:58 -0500
From: cobb
Message-id: <9304221436.AA12784@tango.mcs.anl.gov>
To: mcs
Subject: Seminar Reminder

Argonne National Laboratory
Mathematics and Computer Science Division
SEMINAR
New Methods for Ab Initio Calculations on Very Large Systems
Jan Almlof
University of Minnesota
Minneapolis, MN
10:30AM, Thursday, April 22, 1993
Building 221, Conference Room A216
Abstract
The talk will present several unconventional approaches that can be
used to avoid bottlenecks which are usually encountered in ab initio
quantum chemistry.
I will give a brief overview of the latest development in direct
techniques. These methods were introduced in Hartree-Fock
calculations some time ago, and are now being refined and extended to
encompass correlated electronic structure methods. By avoiding the
storage of integrals, it is obvious that disk size limitations are
completely circumvented. Less obvious but equally important is the
fact that in the direct scheme one can avoid the calculation and
processing of four-center, two-electron integrals altogether.
Techniques to exploit this feature will also be discussed in the
talk.
As the systems under study become larger, it is possible to introduce
very important simplifications due to their `semi-classical'
behaviour in the macroscopic limit, using techniques and concepts
familiar from density functional theory. I will discuss such
techniques, and try to predict how they will affect computational
chemistry in the future. Finally, I will also describe how the
development and application of these methods are being influenced by
recent progress in computer hardware, especially by the emerging
parallel computing technology.
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Coffee and Donuts will be served in the interaction room prior to the
presentation.