{{Short description|British-Canadian scientist and author}} {{Infobox scientist |name = Philip R. Bunker |birth_date = {{birth date and age|df=y|1941|06|29}} |birth_place = London, England |image = Philip Bunker.jpg |spouse = |children = |awards = Humboldt Prize 1995 |citizenship = British <br /> Canadian |alma_mater = King's College London (B.Sc.) University of Cambridge (Ph.D.) |doctoral_advisor = Christopher Longuet-Higgins<ref>{{MathGenealogy|id=83473}}</ref> |doctoral_students = |notable_students = |field = theoretical chemistry <br /> molecular spectroscopy |work_institution = National Research Council of Canada |known_for = molecular symmetry <br /> methylene (CH<sub>2</sub>) <br /> dimethylacetylene |footnotes = }}
'''Philip R. Bunker''' (born 29 June 1941) is a British-Canadian scientist and author, known for his work in theoretical chemistry and molecular spectroscopy.
==Education and early work==
Philip Bunker was educated at Battersea Grammar School in Streatham. He received a bachelor's degree at King's College in 1962 and earned a Ph.D. in theoretical chemistry from Cambridge University in 1965, advised by H.C. Longuet-Higgins. The subject of his Ph.D. thesis was the spectrum of the dimethylacetylene molecule and its torsional barrier.<ref>{{cite journal |author1=P.R. Bunker |author2=H.C. Longuet-Higgins |title=The Infrared Spectrum of Dimethylacetylene and the Torsional Barrier | journal = Proc. R. Soc. A| volume = 280 |page = 340 | year=1964 |issue=1382 | doi = 10.1098/rspa.1964.0149|bibcode=1964RSPSA.280..340B |s2cid=94724543 }}</ref> During Bunker's Ph.D. work in 1963, Longuet-Higgins published the paper that introduced molecular symmetry groups consisting of feasible nuclear permutations and permutation-inversions.<ref name=Longuet-Higgins1963> {{cite journal | last1 = Longuet-Higgins | first1 = H.C. | year = 1963 | title = The symmetry groups of non-rigid molecules | journal = Molecular Physics | volume = 6 | issue = 5| pages = 445–460 | doi = 10.1080/00268976300100501 | bibcode = 1963MolPh...6..445L | doi-access = free }}</ref> Under the guidance of Longuet-Higgins, Bunker applied these new symmetry ideas and introduced the notations G<sub>36</sub> and G<sub>100</sub> for the molecular symmetry groups of dimethylacetylene and ferrocene, respectively.<ref>{{cite journal | author1=P. R. Bunker | year=1964 | title=The Rotation-Torsion Wavefunctions of Molecules that have two Identical Rotors | journal=Mol. Phys. | volume=8 | page=81 | doi = 10.1080/00268976400100091}}</ref> After obtaining his Ph.D. degree, he was a postdoctoral fellow with Jon T. Hougen in the spectroscopy group of Gerhard Herzberg at the National Research Council of Canada. He then spent his entire career at the National Research Council of Canada, eventually rising to the position of principal research officer in 1997.<ref name=chemphyswebsite2021> {{cite web |title=Theory and Simulation Group of the National Research Council of Canada |url=https://chemphys.ca/people/ |access-date=30 July 2021}}</ref>
==Career and important contributions== Philip Bunker's published scientific work has focused on the use of fundamental quantum mechanics to predict and interpret the spectral properties of polyatomic molecules due to their combined rotational, vibrational, electronic and nuclear-spin states, and their symmetries. He has been particularly concerned with the study of the energy levels and spectra of molecules that undergo large amplitude vibrational motions.<ref>{{cite journal |author1=J. T. Hougen |author2=P. R. Bunker |author3=J. W. C. Johns|title=The vibration-rotation problem in triatomic molecules allowing for a large amplitude bending| journal = J Mol Spectrosc | volume = 34 | page= 136 | year = 1970 | bibcode=1970JMoSp..34..136H| doi = 10.1016/0022-2852(70)90080-9}}</ref><ref>{{cite journal |author1=P. R. Bunker |title=Quasilinear and quasiplanar molecules | journal = Annu. Rev. Phys. Chem. | volume = 34 | page= 59 | year = 1983 |doi = 10.1146/annurev.pc.34.100183.000423|bibcode=1983ARPC...34...59B }}</ref> Applications of this work to the methylene (CH<sub>2</sub>) molecule proved to be important in determining the separation between the singlet and triplet electronic states, and in determining which singlet and triplet rotational levels interact.<ref>{{cite journal |author1=A.R.W. McKellar |author2=P.R. Bunker |author3=T.J. Sears |author4=K.M. Evenson |author5=R.J. Saykally |author6=S.R. Langhoff |title= Far Infrared Laser Magnetic Resonance of Singlet Methylene. Singlet-Triplet Perturbations, Singlet-Triplet Transitions, and the Singlet-Triplet Splitting | journal = J Chem Phys | volume = 79 | page = 5251| year=1983|issue=11 | bibcode=1983JChPh..79.5251M| doi = 10.1063/1.445713|doi-access=free}}</ref><ref>P.R. Bunker, 'The Spectrum, Structure, and Singlet-Triplet Splitting in Methylene CH<sub>2</sub>.' Chapter in ‘Comparison of Ab Initio Quantum Chemistry with Experiment for small molecules’, ed. Rodney J. Bartlett, Reidel Dordrecht The Netherlands (1985). https://doi.org/10.1007/978-94-009-5474-8_6</ref> In the 1990s, he returned to the problem of determining the torsional barrier in dimethylacetylene after Robert McKellar and John Johns, experimentalists at the National Research Council of Canada, had obtained a very high resolution infrared spectrum of the molecule.<ref>{{cite journal |author1=C. di Lauro |author2=P. R. Bunker |author3=J. W. C. Johns |author4=A. R. W. McKellar | year = 1997 | title =The rotation-torsion structure in the ν11/ν15 (Gs) methyl rocking fundamental band in dimethylacetylene | journal = J. Mol. Spectrosc.| volume = 184 | issue = 1 | pages = 177–185 | doi =10.1006/jmsp.1997.7321|bibcode=1997JMoSp.184..177L }}</ref>
Bunker is a well-known expert in the use of the molecular symmetry group.<ref>P.R. Bunker 'Practically Everything you Ought to know about the Molecular Symmetry Group' in, ‘Vibrational Spectra and Structure, Vol. III’, ed. James R. Durig, Marcel Dekker (1975). https://chemphys.ca/pbunker/P-Everything.ONE.pdf</ref><ref>{{cite journal |title=Philip R. Bunker and A. Robert W. McKellar Special Issue |journal=Journal of Molecular Spectroscopy |date=May 2011 |volume=267 |issue=1–2 |doi=10.1016/j.jms.2011.04.021 |url=https://doi.org/10.1016/j.jms.2011.04.021 |access-date=30 July 2021|last1=Xu |first1=Yunjie |last2=Jäger |first2=Wolfgang |pages=1–2 |bibcode=2011JMoSp.267....1X |url-access=subscription }}</ref> At the end of Longuet-Higgins' paper in which he introduced permutation and permutation-inversion molecular symmetry groups,<ref name=Longuet-Higgins1963/> Longuet-Higgins wrote: "In conclusion it should be added that the present definition can be extended to linear molecules, and to molecules where spin-orbit coupling is strong; but these topics are best dealt with separately." However, a few years later (in 1967) Longuet-Higgins left the field of theoretical chemistry; he wrote nothing more about molecular symmetry and did not make these extensions. Bunker then developed the extensions of these principles to linear molecules<ref> {{cite journal |author1=P.R. Bunker |author2=D. Papousek | year=1969 | title=The Symmetry Groups of Linear Molecules | journal=J. Mol. Spectrosc. |volume=32 |issue=3 | page=419 | doi=10.1016/0022-2852(69)90007-1|bibcode=1969JMoSp..32..419B }}</ref> as well as to molecules with strong spin-orbit coupling.<ref> P.R. Bunker, 'The Spin Double Groups of Molecular Symmetry Groups,' Chapter in ‘The Permutation Group in Physics and Chemistry. Lecture Notes in Chemistry’, ed. J. Hinze, Springer-Verlag, volume 12 (1979). https://doi.org/10.1007/978-3-642-93124-6_4</ref> Bunker is also known for his work in the quantitative description of non-adiabatic effects in quantum molecular dynamics.<ref>{{cite journal |author1=P.R. Bunker |author2=R.E. Moss| year=1980 | title=The Effect of the Breakdown of the Born-Oppenheimer Approximation on the Rotation-Vibration Hamiltonian of a Triatomic Molecule | journal = J. Mol. Spectrosc. | volume=80 |issue=1 | page=217 | doi = 10.1016/0022-2852(80)90283-0|bibcode=1980JMoSp..80..217B }}</ref><ref>Per Jensen, G. Osmann and P. R. Bunker 'The Renner Effect.' Chapter 15 in ‘Computational Molecular Spectroscopy’, eds. P. Jensen and P. R. Bunker, Wiley, Chichester, (2000) {{ISBN|0-471-48998-0}} [https://www.wiley.com/en-br/Computational+Molecular+Spectroscopy-p-9780471489986]</ref>
Together with Per Jensen (1956-2022), who was a theoretical chemist at Bergische Universität Wuppertal,<ref>{{cite web |title=Prof Per Jensen |url=https://www.gatheringus.com/memorial/prof-per-jensen/9264?locale=en_US&c=973 |access-date=20 July 2022}}</ref> Bunker has written two books on theoretical chemistry and molecular spectroscopy; ''Molecular Symmetry and Spectroscopy'' (1998)<ref>P. R. Bunker and Per Jensen (1998), ''Molecular Symmetry and Spectroscopy'', 2nd ed., NRC Research Press, Ottawa {{ISBN|9780660196282}}[https://volumesdirect.com/products/molecular-symmetry-and-spectroscopy?_pos=1&_sid=ed0cc0319&_ss=r]</ref> and ''Fundamentals of Molecular Symmetry'' (2005).<ref>P. R. Bunker and Per Jensen (2005), ''Fundamentals of Molecular Symmetry'' (CRC Press) {{ISBN|0-7503-0941-5}} [https://www.routledge.com/Fundamentals-of-Molecular-Symmetry/Bunker-Jensen/p/book/9780750309417]</ref> Currently, Bunker is Researcher Emeritus at the National Research Council of Canada and a guest scientist at the Fritz-Haber Institute of the Max Planck Society.<ref>{{cite web |title=Fritz Haber Institute: Collaborations |url=https://www.fhi.mpg.de/210902/Collaborations |access-date=27 January 2022}}</ref> He has also held visiting scientist positions at universities and institutions around the world during the course of his career, including ETH-Zurich, Massey University, Kyushu University and University of Florence.<ref name=chemphyswebsite2021/> During the course of his career he has delivered over 400 invited lectures.<ref name=chemphyswebsite2021/>
==Awards and honors== Bunker received the Humboldt Prize (1995), the Medaili Jana Marca Marci of the Czech Spectroscopy Society (2002),<ref>{{cite web |title=Nositelé medaile Jana Marka Marci z Kronlandu |url=http://www.spektroskopie.cz/?q=oceneni_medaileJMM |publisher=Spektroskopická společnost Jana Marka Marci, o.s. |access-date=26 August 2022}}</ref> and the 2002 Sir Harold Thompson Memorial Award, which is sponsored by Pergamon Press (now Elsevier) for the most significant advance in spectroscopy published in Spectrochimica Acta each year.<ref>{{cite journal |title=Editorial Announcement: Sir Harold Thompson Memorial Award |journal=Spectrochimica Acta |date=1986 |volume=42A |issue=6 |page=i}}</ref> He is a Fellow of the International Union of Pure and Applied Chemistry.<ref>{{cite web |title=BUNKER, Dr. Philip R. |url=http://publications.iupac.org/organ/members/b/bunker.html |publisher=IUPAC |access-date=21 July 2022}}</ref>
==Personal life== Bunker married Eva Cservenits in 1966. Their son, Alex E. Bunker, is a computational biophysicist at the University of Helsinki.<ref>{{cite web |title=Alex Edwin Bunker |url=https://researchportal.helsinki.fi/en/persons/alex-edwin-bunker |publisher=University of Helsinki |access-date=26 August 2022}}</ref>
==References== {{Reflist}}
==Selected presentations== * {{cite web | last=Bunker | first=P. R. | title=Near symmetry in our universe: The origin of life and the preponderance of matter over antimatter | publisher=Ohio State University | date=2008 | url=https://kb.osu.edu/handle/1811/33295 | access-date=25 July 2023}} *{{YouTube|0nV9f5uqul0&t|“The Planck constant and its units,” The 35th Symposium on Chemical Physics at the University of Waterloo, Ontario, Canada, November 3, 2019.}}
==External links== *Medaili Jana Marca Marci. https://lcms.cz/companies/7 *Prof. Bunker's personal web site at https://chemphys.ca/pbunker/ *From Battersea Grammar School Magazine, 1959 Autumn Term. Courtesy of the [https://bgsoldgrammarians.org/ Old Grammarians website]. {{Portal bar|Biography|Canada|Chemistry|Books|Science}}
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{{DEFAULTSORT:Bunker, Philip R.}} Category:Living people Category:Canadian chemists Category:Spectroscopists Category:National Research Council (Canada) Category:Alumni of King's College London Category:1941 births