It has been a great pleasure for me to act as Guest Editor of this special issue of the Journal of Solid State Chemistry, honoring the 60th birthday of Peter Day. Peter's in#uence on my scienti"c career has been pivotal and our close scienti"c association has spanned a period of more than two decades, beginning with my graduate studies in Oxford and continuing to the present day. The present issue is partially based on the contributions made by some of Peter's numerous research students, associates, and colleagues to the special symposium Electronic Processes in Inorganic Compounds, organized by the Royal Institution of Great Britain (in association with the Dalton Division, the Faraday Division, the Materials Chemistry Forum, and the Solid State Chemistry Group of the Royal Society of Chemistry) in June 1998 to honor his lifelong contribution to inorganic chemistry, on the occasion of his 60th birthday. The breadth of the research topics addressed in this issue re#ects the interdisciplinary scope of Peter's research interests and accomplishments.
Peter Day was born in September 1938 in Wrotham, Kent, and educated at the nearby grammar school at Maidstone. He was a Scholar, and subsequently a graduate student at Wadham College, Oxford, of which he is now an Honorary Fellow. His doctoral research, carried out in Oxford and Geneva, initiated the modern day study of inorganic mixed valency compounds.