Per-Olov Löwdin (October 28, 1916 – 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.

Per-Olov Löwdin
Born(1916-10-28)October 28, 1916
Uppsala, Sweden
DiedOctober 6, 2000(2000-10-06) (aged 83)
Uppsala, Sweden
NationalitySwedish
Alma materUppsala University
Known forLöwdin perturbation theory
Löwdin rules
Löwdin weights
Natural bond orbital
Orthogonalization
Proton tunneling
Quantum biology
AwardsNiels Bohr Medal (1987)
Lavoisier Medal (1975)
St. Olav's Medal (1975)
Björkénska priset (1973)
Scientific career
FieldsQuantum chemistry
InstitutionsUniversity of Uppsala
University of Florida
Doctoral advisorIvar Waller

A former graduate student under Ivar Waller, Löwdin formulated in 1950 the symmetric orthogonalization scheme for atomic and molecular orbital calculations, greatly simplifying the tight-binding method.[1][2] This scheme is the basis of the zero-differential overlap (ZDO) approximation used in semiempirical theories. In 1956 he introduced the canonical orthogonalization scheme, which is optimal for eliminating approximate linear dependencies of a basis set.[3] These orthogonalization procedures are widely used today in all modern quantum chemistry calculations.[4][5]

The famous 'Löwdin's pairing theorem' used in restricted open-shell Hartree–Fock (ROHF), unrestricted Hartree–Fock (UHF) and generalized valence bond (RES-GVB) theories is not his. According to himself, George G. Hall and King made the formal proposition after an informal suggestion by Löwdin.[citation needed]

His Löwdin 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 and 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.

Löwdin was elected a member of the Royal Swedish Academy of Sciences in 1969, the American Philosophical Society in 1983,[6] and was a member of the committee for the Nobel Prize in Physics from 1972 to 1984. He was 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.

Publications

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Publications

References

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  1. ^ Löwdin, Per-Olov (1950). "On the non-orthogonality problem connected with the use of atomic wave functions in the theory of molecules and crystals". The Journal of Chemical Physics. 18 (3): 365. Bibcode:1950JChPh..18..365L. doi:10.1063/1.1747632.
  2. ^ J. C. Slater and G. F. Koster, Phys. Rev.94, 1498 (1954).
  3. ^ Löwdin, Per-Olov (1956). "Quantum theory of cohesive properties of solids". Advances in Physics. 5 (17): 1. Bibcode:1956AdPhy...5....1L. doi:10.1080/00018735600101155.
  4. ^ Reed, Alan E., Larry A. Curtiss, and Frank Weinhold. "Intermolecular interactions from a natural bond orbital, donor-acceptor viewpoint." Chemical Reviews 88.6 (1988): 899-926.
  5. ^ Lu, Tian; Chen, Feiwu (2012). "Multiwfn: A multifunctional wavefunction analyzer". Journal of Computational Chemistry. 33 (5): 580–592. doi:10.1002/jcc.22885. PMID 22162017. S2CID 13508697.
  6. ^ "APS Member History". search.amphilsoc.org. Retrieved 2022-05-31.
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