This volume and its two companion volumes, entitled Tetrahedrally-Bonded
Amorphous Semiconductors and Localization and Metal-Insulator
Transitions, are our way of paying special tribute to Sir Nevill Mott
and to express our heartfelt wishes to him on the occasion of his
eightieth birthday. Sir Nevill has set the highest standards as a
physicist, teacher, and scientific leader. Our feelings for him include
not only the respect and admiration due a great scientist, but also a
deep affection for a great human being, who possesses a rare combination
of outstanding personal qualities. We thank him for enriching our lives,
and we shall forever carry cherished memories of this noble man.
Scientists best express their thanks by contributing their thoughts and
observations to a Festschrift. This one honoring Sir Nevill fills three
volumes, with literally hundreds of authors meeting a strict deadline.
The fact that contributions poured in from all parts of the world
attests to the international cohesion of our scientific community. It is
a tribute to Sir Nevill's stand for peace and understanding,
transcending national borders. The editors wish to express their
gratitude to Ghazaleh Koefod for her diligence and expertise in
deciphering and typing many of the papers, as well as helping in
numerous other ways. The blame for the errors that remain belongs to the
editors.