This volume and its two companion volumes, entitled Tetrahedrally-Bonded
Amorphous Semiconductors and Physics of Disordered Materials, 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.