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Isaiah Shavitt
Isaiah Shavitt was a Polish-born Israeli and American theoretical chemist. He was born Isaiah Kruk on July 29, 1925 in Kutno, Poland but his family moved to what would become Israel in 1929. After undergraduate degrees in chemistry (1950) and chemical engineering (1951) from the Technion in Haifa, he started a Ph.D. in experimental physical chemistry, but shortly after traveled to Cambridge University on a British Council Scholarship and completed his Ph.D. (1957) under the aegis of pioneering computational chemist S. Francis Boys. Following postdoctoral work with Joseph O. Hirschfelder, a stint as a temporary assistant professor at Brandeis University, and further postdoctoral research with Martin Karplus, he became a professor at his alma mater in 1962. In 1967 he moved to a senior research position at Battelle Memorial Institute in Columbus, Ohio, United States. In 1968 he also became a part-time faculty member at the Department of Chemistry at Ohio State University and moved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Chemist
Theoretical chemistry is the branch of chemistry which develops theoretical generalizations that are part of the theoretical arsenal of modern chemistry: for example, the concepts of chemical bonding, chemical reaction, valence, the surface of potential energy, molecular orbitals, orbital interactions, and molecule activation. Overview Theoretical chemistry unites principles and concepts common to all branches of chemistry. Within the framework of theoretical chemistry, there is a systematization of chemical laws, principles and rules, their refinement and detailing, the construction of a hierarchy. The central place in theoretical chemistry is occupied by the doctrine of the interconnection of the structure and properties of molecular systems. It uses mathematical and physical methods to explain the structures and dynamics of chemical systems and to correlate, understand, and predict their thermodynamic and kinetic properties. In the most general sense, it is explanation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Academy Of Quantum Molecular Science
The International Academy of Quantum Molecular Science (IAQMS) is an international scientific learned society covering all applications of quantum theory to chemistry and chemical physics. It was created in Menton in 1967. The founding members were Raymond Daudel, Per-Olov Löwdin, Robert G. Parr, John Pople and Bernard Pullman. Its foundation was supported by Louis de Broglie. Originally the Academy had 25 regular members under 65 years of age. This was later raised to 30, and then to 35. There is no limit on the number of members over 65 years of age. The members are "chosen among the scientists of all countries who have distinguished themselves by the value of their scientific work, their role of pioneer or leader of a school in the broad field of quantum chemistry, i.e. the application of quantum mechanics to the study of molecules and macromolecules". The Academy presently consists of 90 members (as of 2006). The Academy organizes the International Congress of Quantum Chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Physical Chemistry
''The Journal of Physical Chemistry A'' is a scientific journal which reports research on the chemistry of molecules - including their dynamics, spectroscopy, kinetics, structure, bonding, and quantum chemistry. It is published weekly by the American Chemical Society. Before 1997 the title was simply ''Journal of Physical Chemistry''. Owing to the ever-growing amount of research in the area, in 1997 the journal was split into ''Journal of Physical Chemistry A'' (molecular theoretical and experimental physical chemistry) and '' The Journal of Physical Chemistry B'' (solid state, soft matter, liquids, etc.). Beginning in 2007, the latter underwent a further split, with ''The Journal of Physical Chemistry C'' now being dedicated to nanotechnology, molecular electronics, and related subjects. Editors-in-chief *1896–1932 Wilder Dwight Bancroft, Joseph E. Trevor *1933–1951 S. C. Lind *1952–1964 William A. Noyes *1965–1969 F. T. Wall *1970–1980 Bryce Crawford *1980–2004 Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
St Catharine's College, Cambridge
St Catharine's College is a constituent college of the University of Cambridge. Founded in 1473 as Katharine Hall, it adopted its current name in 1860. The college is nicknamed "Catz". The college is located in the historic city-centre of Cambridge, and lies just south of King's College and across the street from Corpus Christi College. The college is notable for its open court (rather than closed quadrangle) that faces towards Trumpington Street. St Catharine's is unique in being the only Oxbridge college founded by the serving head of another college. The college community is moderately sized, consisting of approximately 70 fellows, 150 graduate students, and 410 undergraduates. History Foundation Robert Woodlark, Provost of King’s College, had begun preparations for the founding of a new college as early as 1459 when he bought tenements on which the new college could be built. The preparation cost him a great deal of his private fortune (he was suspected of divert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ab Initio Quantum Chemistry Methods
''Ab initio'' quantum chemistry methods are computational chemistry methods based on quantum chemistry. The term was first used in quantum chemistry by Robert Parr and coworkers, including David Craig in a semiempirical study on the excited states of benzene. The background is described by Parr. ''Ab initio'' means "from first principles" or "from the beginning", implying that the only inputs into an ''ab initio'' calculation are physical constants. ''Ab initio'' quantum chemistry methods attempt to solve the electronic Schrödinger equation given the positions of the nuclei and the number of electrons in order to yield useful information such as electron densities, energies and other properties of the system. The ability to run these calculations has enabled theoretical chemists to solve a range of problems and their importance is highlighted by the awarding of the Nobel prize to John Pople and Walter Kohn. Accuracy and scaling ''Ab initio'' electronic structure method ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
COLUMBUS
Columbus is a Latinized version of the Italian surname "''Colombo''". It most commonly refers to: * Christopher Columbus (1451-1506), the Italian explorer * Columbus, Ohio, capital of the U.S. state of Ohio Columbus may also refer to: Places Extraterrestrial * Columbus (crater), a crater on Mars * ''Columbus'' (ISS module), the European module for the International Space Station * ''Columbus'' (spacecraft), a program to develop a European space station 1986–1991 Italy * Columbus (Rome), a residential district United States * Columbus, Arkansas * Columbus, Georgia * Columbus, Illinois * Columbus, Indiana, known for modern architecture * Columbus, Kansas * Columbus, Kentucky * Columbus, Minnesota * Columbus, Mississippi * Columbus, Missouri * Columbus, Montana * Columbus, Nebraska * Columbus, New Jersey * Columbus, New Mexico * Columbus, New York * Columbus, North Carolina * Columbus, North Dakota * Columbus, Ohio, the largest city in United States with this name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coupled Cluster
Coupled cluster (CC) is a numerical technique used for describing many-body systems. Its most common use is as one of several post-Hartree–Fock ab initio quantum chemistry methods in the field of computational chemistry, but it is also used in nuclear physics. Coupled cluster essentially takes the basic Hartree–Fock molecular orbital method and constructs multi-electron wavefunctions using the exponential cluster operator to account for electron correlation. Some of the most accurate calculations for small to medium-sized molecules use this method. The method was initially developed by Fritz Coester and Hermann Kümmel in the 1950s for studying nuclear-physics phenomena, but became more frequently used when in 1966 Jiří Čížek (and later together with Josef Paldus) reformulated the method for electron correlation in atoms and molecules. It is now one of the most prevalent methods in quantum chemistry that includes electronic correlation. CC theory is simply the pertur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Configuration Interaction
Configuration interaction (CI) is a post-Hartree–Fock linear variational method for solving the nonrelativistic Schrödinger equation within the Born–Oppenheimer approximation for a quantum chemical multi-electron system. Mathematically, ''configuration'' simply describes the linear combination of Slater determinants used for the wave function. In terms of a specification of orbital occupation (for instance, (1s)2(2s)2(2p)1...), ''interaction'' means the mixing (interaction) of different electronic configurations (states). Due to the long CPU time and large memory required for CI calculations, the method is limited to relatively small systems. In contrast to the Hartree–Fock method, in order to account for electron correlation, CI uses a variational wave function that is a linear combination of configuration state functions (CSFs) built from spin orbitals (denoted by the superscript ''SO''), : \Psi = \sum_ c_ \Phi_^ = c_0\Phi_0^ + c_1\Phi_1^ + where Ψ is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaussian-type Orbital
In computational chemistry and molecular physics, Gaussian orbitals (also known as Gaussian type orbitals, GTOs or Gaussians) are functions used as atomic orbitals in the LCAO method for the representation of electron orbitals in molecules and numerous properties that depend on these. Rationale The use of Gaussian orbitals in electronic structure theory (instead of the more physical Slater-type orbitals) was first proposed by Boys in 1950. The principal reason for the use of Gaussian basis functions in molecular quantum chemical calculations is the 'Gaussian Product Theorem', which guarantees that the product of two GTOs centered on two different atoms is a finite sum of Gaussians centered on a point along the axis connecting them. In this manner, four-center integrals can be reduced to finite sums of two-center integrals, and in a next step to finite sums of one-center integrals. The speedup by 4-5 orders of magnitude compared to Slater orbitals outweighs the extra cost entailed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slater-type Orbital
Slater-type orbitals (STOs) are functions used as atomic orbitals in the linear combination of atomic orbitals molecular orbital method. They are named after the physicist John C. Slater, who introduced them in 1930. They possess exponential decay at long range and Kato's cusp condition at short range (when combined as hydrogen-like atom functions, i.e. the analytical solutions of the stationary Schrödinger equation for one electron atoms). Unlike the hydrogen-like ("hydrogenic") Schrödinger orbitals, STOs have no radial nodes (neither do Gaussian-type orbitals). Definition STOs have the following radial part: : R(r) = N r^ e^\, where * is a natural number that plays the role of principal quantum number, = 1,2,..., * is a normalizing constant, * is the distance of the electron from the atomic nucleus, and * \zeta is a constant related to the effective charge of the nucleus, the nuclear charge being partly shielded by electrons. Historically, the effective nuclear charge was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
