Enquist, Per Olov, 1934-, Swedish novelist and dramatist. During a highly productive period in the 1960s and 70s and frequently thereafter, Enquist has based much of his work on historical figures and events. His novel The Legionnaires (1968, tr. 1973) examines the life of refugees in Sweden after World War II. His popular play The Night of the Tribades (1975, tr. 1977) examines the private life of playwright August Strindberg, and the drama Bildmakarna [the picture makers] (1998) features Selma Lagerlöf as one of its four characters. Enquist's later novels include Nedstortad Angel (1987, tr. Downfall, 1991), I Lodjurets Timma (1988, tr. Hour of the Lynx, 1990), Kapten Nemos Bibliotek [Captain Nemo's library] (1991), and Livläkarens Besök (1999, tr. The Royal Physician's Visit, 2001). Enquist's fiction often provides social criticism from his position on the political left. Enquist has written screenplays for Hamsun (1996) and Magnetisörens femte vinter [the magnetist's fifth winter] (1997), an adaptation of his 1964 novel (and first major book) of the same name. His other works include short stories and travel books.

Per-Olov Löwdin (born October 28, 1916 in Uppsala, Sweden, died October 6, 2000) was a Swedish physicist, professor at the University of Uppsala from 1960 to 1983, and in parallel at the University of Florida until 1993.

A former graduate student under [Ivar Waller], Löwdin formulated in 1950 the symmetric orthogonalization scheme for molecular orbital calculations. This scheme is the basis of the zero-differential overlap (ZDO) approximation used in semiempirical theories.

He is also credited with the use of fat symbols for matrices, making easy the derivation of several theorems of quantum mechanics.

The famous 'Löwdin pairing theorem' used in ROHF, UHF and RES-GVB theories is not his. According to himself, George G. Hall and King made the formal proposition after an informal suggestion by Löwdin.

His partitioning technique for quantum chemistry problems is best appreciated through the series of 14 papers on Perturbation Theory published between 1963 and 1971.

He was also a very active teacher, starting the Summer Schools of Quantum Chemistry at Uppsala around 1958. In 1959-1960 Löwdin started the Quantum Theory Project at the University of Florida as a sister project to the Uppsala Quantum Chemistry Group. In 1964 he was joined by John C. Slater from MIT. The International Winter Institutes (held initially at Sanibel Island, and later at Gainesville) provided the initiation of hundreds of Latin American young scientists during the eighties and nineties. In 1960 he founded the Sanibel Symposium in conjunction with the Winter Institute. They have been held every year since 1960 with the 47th symposium held in 2007.

Löwdin was a member of the committee for the Nobel Prize in physics for many years, and the founder of the International Journal of Quantum Chemistry and of the series Advances in Quantum Chemistry. He was a foundation member of the International Academy of Quantum Molecular Science.

External links

• Short article in University of Florida bulletin
• The Löwdin Lectures, Uppsala University
• Quantum Theory Project founded by Löwdin at the University of Florida in 1960