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    COLLOQUIUM OF THE LABORATORY FOR COMPUTER DESIGN OF MATERIALS
        Institute for Computational Sciences and Informatics
	                      CSI 898-Sec 001  
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		First-principles Studies of Ferroelectrics

				Ronald Cohen
	Geophysical Laboratory, Carnegie Institution of Washington

Ferroelectrics form a important class of technological materials for
applications as acoustic transducers and sensors, dielectrics,
mechanical actuators, switches, oscillators and filters, but a
fundamental theory of ferroelectrics and their properties is only
now being developed. Recent advances include the study of the
underlying potential and atomic interactions in ferroelectrics,
development of an understanding of the origins of ferroelectricity,
the theory and computation of polarization, and Born effective
charges, and only now the first-principles computation of
piezoelectric constants. We can now compute all of the parameters
that describe electromechanical coupling in these materials from
first-principles. Agreement is generally good with experiment, and
eventually these methods will allow the computational design of
ferroelectrics for applications.

	                 Monday, April 13 1998
                                 4:30 pm
                        Room 206, Science & Tech. I

Refreshments will be served.
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(http://www.csi.gmu.edu/lcdm/seminar/schedule.html)