REPORT RESUMESE 020 904 SE 004 901DEVELOPMENT OF A MULTI - COORDINATE VOCABULARY, CHEMICALPHYSICS.BY- LERNER, RITA G.AMERICAN INST. OF PHYSICS, NEW YORK, N.Y.

EDRS PRICE MFS0.25 HC -$1.04 24P.

PUB DATE MAR 68

DESCRIPTORS- *COLLEGE SCIENCE, *CHEMISTRY, *INFORMATIONSCIENCE, *INFORMATION RETRIEVAL, *THESAURI, VOCABULARY,GRADUATE STUDY, PHYSICS, SCIENTIFIC RESEARCH, AMERICANINSTITUTE OF PHYSICS, NATIONAL SCIENCE FOUNDATION,

THIS PAPER DESCRIBES A METHOD (SCHEME) FOR THEDEVELOPMENT OF A VOCABULARY IN THE FIELD OF CHEMICAL PHYSICSFROM PRIMARY JOURNAL ARTICLES. ALL TERMS APPEARING IN ARECENT JOURNAL (VOL. 39, JOURNAL OF CHEMICAL PHYSICS) JUDGEDTO BE IMPORTANT WERE DIVIDED INTO THREE CATEGORIES - -(1)PROPERTIES, PROCESSES, PHENOMENA, (2) OBJECTS, INCLUDINGSYSTEMS AND MATERIALS, AND (3) METHODS, INCLUDING DEVICES. INADDITION TO THESE THREE CLASSIFICATIONS, TERMS SPECIFYINGSPECIAL CONDITIONS WERE ALSO USED SUCH AS MASS, ENERGY, ANDTEMPERATURE. BY THE THREE MAJOR CLASSIFICATIONS ANDAPPROPRIATE ADDITIONAL TERMS DESCRIBING CONDITIONS, AMULTI - COORDINATED INDEX IS ESTABLISHED. THE THESAURUS WASREVIEWED BY SPECIALISTS WHO GAVE SUGGESTIONS FOR REVISIONSAND ADDITIONS. ADDITIONAL TERMS WERE ADDED IN THE PROCESS OFUSING THE THESAURUS IN EXPERIMENTAL RETRIEVAL. THE COMPLETEVOCABULARY IS INCLUDED IN THE PAPER. METHODS USED TO DEVELOPTHIS THESAURUS WERE ALSO USED TO DEVELOP THESAURI FOR THEFIELDS OF PLASMA'PHYSICS AND LASERS AND MASERS. THE PAPERSWHICH WERE INDEXED ACCORDING TO THIS SYSTEM FORM THE DATABASE FOR A NUMBER OF EXPERIMENTS CURRENTLY BEING CONDUCTED ONRETRIEVAL MECHANISMS. (DH)

iNcoitravat°

Received in RSP___i47/6". ID 68-3No. of copies Otlarch 1968)

Grant (Confact )

U.S. DEPARTMENT OF HEALTH, EDUCATION & WELFARE

OFFICE OF EDUCATION

THIS DOCUMENT HAS BEEN REPRODUCED EXACTLY AS RECEIVED FROM THE

PERSON OR ORGANIZATION ORIGINATING IT. POINTS OF VIEW OR OPINIONS

STATED DO NOT NECESSARILY REPRESENT OFFICIAL OFFICE OF EDUCATION

POSITION OR POLICY.

DEVELOPMENT OF A MULTI-COORDINATE VOCABULARY:

CHEMICAL PHYSICS

Rita G. Lerner

e

Information Division

AMERICAN INSTITUTE OF PHYSICS 335 East 45 Street, New York, N.Y. 10017

This program supported by the National ScienceFoundation under Grant No. NSF-GN-549

si;:sH--:AP'llt,l'.

3r

ales Gq01111,1

Umelopment of a Italti-coordinate Toca'bularyChemical 'f 7-* as

(1* Ieruer

A umber ot thesauri have been created in the past byins together groups ot subject experts to dortiermine relevantterms or cku merging lists o terms derived from varioussources /Atkin a field* Ws payer describes a methoi o creating of a vocabulary derived from primary jointnal azottelesoThe method is applied to the deve cit a vocabulary inthe field of cheerical pbysics, vocabulan takes the formof a set of authority lists*

chemical us vocabulary ees created direrotly from a grom or era,-

shed in the larg3st journal in the field of chemical

of the *Irournal of Chemical ftwics (a total of about :41+ articles) was read *troughs

and all terms appearing in the titles abstract or bay of the paper which were

judged to be important terms the author were placed on cards* Taking the deft-

nation of les to be tbe study of the primes of objects by methodssa it

sib to divide the cards into the following lists or

1. Properties, Processes and Phenomena*

2. Objects, inclaing systems and materials*

3. Methods, including devices*

kiditional terms describe whether the paper is experimental, oretical or baths

and special conditions such as mass,. euerws frequency's temperature or pressure

mos ace can then classify a paper by assigning one or = s ptors from

the

4.-4006,9(

Vuloy de

Vie- is plus appropriate additional terms describi itiones

Wi*ng a multi-coordinate index*

The thesaurus develmed in s manner contained only terms rent 0- to

articles mewing in Yo* 39 of JttSt It was then reviewed by subject specialists

11° 410i W

who gave suggestions for revisions and additions Bose additional terms were

xi) 68-3

It

-2-

to the thesaurus as the need for them appeared during the process of indexing

papers for experiments in retrieval. The complete vocabulary appears in

Appendix A.

The list of properties, processes and phenomena is organized hierarchi-

cally, with synonyms or very closely related terms (quasi-synonyms) treated as

one descriptor. Papers are indexed at the most specific level possible, but can

be searched for at a broader level. For example, Fluid Properties has a sub-

heading Fluid Transport Properties, with further subdivisions into terms such as

Thermal Conductivity and Viscosity; Viscosity is further subdivided into Volume

Viscosity and Shear Viscosity. A particular journal article may report an ex-

perimental measurement of Shear Viscosity which may be relevant to the interests

of someone working in the general field of Fluid Transport Properties or may be

of interest to someone who wants the specific measurement. In a computer search,

it should then be possible to ask for all papers on Viscosity or all papers on

Fluid Transport Properties, including Viscosity; in our system it is possible to

cover a range of related terms in a computer search merely by specifying the

first and last terms to be included in the search. For convenience in handling the

indexed papers within the computer, all of our index terms were converted to 7-

digit code numbers, which indicate the coordinate of the term (property, object

or method) as well as the term's level in the hierarchy. An internal dictionary

converts the code numbers back to English language for the printed output.

The list of objects is a faceted list. The facets consist of the follow-

ing:

1. An identification of the physical nature of the object,

e.g., electron, atom, molecule, etc., together with a

nonunique notation of the chemical formula.

1%.

-3-

2. The physical class of the object, i.e., semiconductor,

polymer, etc.3. The physical state of the object, i.e., single crystal,

monolayer film, etc.

4. Systems, such as rigid rotors or spin systems.

5. Shape of the object, used primarily for theoreticalpapers in chemical physics in which a shape must be as-

sumed in order to perform calculations on a particularmodel of the object.

One object has several facets. If the paper deals, however, with the properties

of several objects, the article may be treated as if it were a series of papers,

each object being indexed by the appropriate set of properties.

The list of methods describes experimental and theoretical methods, and

some of the devices used to make measurements. The revised thesaurus was used to

index some 4,000 articles from the Journal of Chemical Physics volumes 41-44 July,

1964 - June, 1966. Examples of indexed papers appear in Appendix B.

The method used to develop this thesaurus was also used to develop the-

sauri for the fields of plasma physics and lasers and masers.

The approximately 850 papers appearing in volume 44 of the Journal of

Chemical Physics which were indexed according to this method form the data base

for several experiments now being conducted on retrieval mechanisms. One of

these is a joint experiment with the Chemical Abstracts Service to determine the

needs of chemical physicists and physical chemists, and the types of indexing

necessary to meet these needs. Another experiment with this data base will pro-

duce a printed index permuted on the property and methods lists. The results of

these experiments will be discussed in later reports.

-4-

Acknowledgment

The author gratefully acknowledges helpful discussions with the following,

during the development of the chemical physics vocabulary:

Prof.

Prof.

Prof.

Prof.

Prof.

Prof.

Prof.

Benjamin P. Dailey

George K. Fraenkel

Martin Goldstein

Martin Karplus

Daniel Kivelson

Jeremy Musher

Irwin Oppenheim

Prof. William Spindel

Columbia University

Columbia University

Yeshiva University

Harvard University

U.C.L.A.

Yeshiva University

M.I.T.

Yeshiva University

APPENDIX ACHEMICAL PHYSICS' VOCABULARY

PROPERTIES, PROCESSES AND PHENOMENA

Acoustics and UltrasonicsSound VelocityUltrasonic Attenuation

Bond StructureBond HybridizationBond Resonance IntegralCovalence and Ionic CharacterConjugation and HyperconjugationElectronegativityHydrogen Bonding

Charge Distribution (see also Electron Properties)

Charge TransferCharge-transfer cross-sectionCharge-transfer energy

Multipole InteractionDipole-Dipole InteractionDipole-Quadrupole InteractionDipole-Induced Dipole InteractionInduced Dipole-Induced Dipole InteractionQuadrupole-Quadrupole Interaction

Electric Field GradientElectronic StructureInduced DipolePolarizabilityNuclear Quadrupole Resonance

SpectraFrequencyIntensityLine ShapeLine Width

QuadrupoleAsymmetry ParameterQuadrupole MomentQuadrupole Coupling Constant

Chemical PropertiesCatalysis

Catalysis, Temperature DependenceHeterogeneous CatalysisHomogeneous Catalysis

Kinetics of ReactionActivation EnergyEquilibriaRates of ReactionReaction Cross-section; Reaction Probability

Reaction MechanismReduction and Oxidation

- A 1 -

PROPERTIES, PROCESSES AND PHENOMENA (CONT.)

Collision Processes and Scattering (see also Energy Transfer)

Angular Distributions and TrajectoriesCollisions

Capture Cross-sectionsCollision Cross-sections; Collision Diameters; Collision Efficiency

Elastic CollisionsInelastic Collisions

ScatteringEnergy-Dependent ScatteringEnergy-Independent ScatteringEnergy-Loss Parameter; Energy Loss SpectraEnergy-transfer Cross-sectionScattering Cross-section

Colloidal PropertiesStabilityMicelle FormationMicelle Structure

Detonation and Shock WavesActivation EnergyMechanism of InitiationInduction Time

Electric and Dielectric PropertiesConductivityDielectric ConstantDielectric LossDielectric Relaxation TimeHysteresisDielectric StrengthIonic MobilityTransport NumberElectrical Resistance

Electron PropertiesElectron Charge DensityElectron Spin DensityElectron TransferRotation-Electron Spin InteractionSpin-Orbit Interaction

Electronic StatesElectronic Spectra

Absorption Cross- section; Absorption CoefficientBand WidthFrequencyIntensityLifetimeStark Effect, Electronic Spectra

Term ValuesTransition ProbabilityElectronic Energy TransferVibronic Coupling

- A 2 -

PROPERTIES, PROCESSES AND PHENOMENA (CONT.)

Energy Transfer (see also Collision Processes and Scattering; Luminescence)

Electronic Energy Transfer

Energy Transfer between rotation and vibrational degrees of freedom

Energy Transfer Cross-section

Energy Transfer Mechanism

Radiationless TransitionThermal. Energy Transfer

Energy Transfer Probability; Transition Probability

Energy Transfer, Translational-Vibrational

Energy Transfer, Electronic-Vibrational

Energy and Potentials (see also Wave Functions, Eigenfunctions and Integrals)

Binding Energy; Dissociation Energy

Charge Transfer EnergyElectron-Electron Repulsion Energy

Electron-Nuclear Attraction Energy

Energy DerivativesEnergy LevelEnergy Level DensityExcitation EnergyGround State EnergyHartree-Fock EnergyInteraction PotentialIonization. Energy; Electron Affinity

Lattice EnergyKinetic EnergyOrbital EnergyPi-electron EnergyPotential Energy; Potential Energy Surface; Barrier'Heights and Widths

Potential Function; Potential Constants

PredissociationRelativistic EnergyResonance EnergyRotational EnergySigma-electron EnergyStrain EnergyTotal EnergyTranslational EnergyTunnelingVibrational Energy

Torsional Energy

Fluid Properties (see also Solutions; Thermodynamic Properties; Transport Propertie

Critical PropertiesCritical. Opalescence

Dielectric Relaxation Time

Equation of StateVirial CoefficientsVolumePressure

Flow BirefringenceInteraction Properties; Intermolecular Interaction

- A 3 -

' , n

484,041104iitZt.l" X424:As3V s .

PROPERTIES, PROCESSES AND PHENOMENA (CONT.

Intramolecular InteractionPair PotentialDistribution Function; Correlation FunctionScattering PotentialFluid Structure; Structural DomainsStructural Relaxation TimeSurface TensionTransport Properties

Diffusion and Self-Diffusion CoefficientsThermal Diffusion CoefficientElectrical ConductivityDensityIonic MobilitySedimentationViscosity

Volume ViscosityShear Viscosity

Thermal ConductivityViscoelastic PropertiesTransport Numbers

Triplet DistributiOnCluster Integrals )1Effusion

Ionic Properties (see also Photoionization)Auto-ionizationDonnan Equilibrium ParameterIonic MobilityIon Exchange

Distribution CoefficientsThickness of effective boundary layers

Kinetic EnergyIon MassIon FormationIonic Vibrational LevelsIonization Potential; Ionization EnergyIonization ProcessesIonization Cross-section; Ion YieldsField Ionization

Isotope Effects (see also Nuclide Properties)Equilibrium Isotope EffectsIntermolecular Isotope EffectsIntramolecular Isotope EffectsIsotope Separation; Isotope Separation Factor.Kinetic Isotope Effects

Laser and Maser Properties

Liquid Crystal PropertiesDomainsElectric and Magnetic Field EffectsOptical Properties

PROPERTIES, PROCESSES AND1HENOMENA (CONT.)

Luminescence (see also Energy Transfer)Spectra

IntensitiesLifetime; Quenching; Quenching Cross-sectionYield

ChemiluminescenceThermoluminescence

Macromolecular Properties (see also Kinetics of Reaction; ThermodynamicTransport Properties)

Donnan Equilibrium ParameterMolecular ShapeMolecular SizeMolecular Weight DistributionPolymer FormationPolymer LengthHydrodynamic Interaction Parameter

Magnetic PropertiesAnisotropy, MagneticAntiferromagnetism

Neel TemperatureCurie TemperatureElectron Parhmagnetic Resonance

Correlation TimeGyromagnetic RatioHyperfine InteractionsRelaxation TimeSpectra

FrequencyLine ShapeLine WidthIntensityDouble Quantum Transitions

Superhyperfine InteractionsZero-field SplittingSpin-Spin Coupling

Magnetic Coupling ConstantMagnetizationMagnetic EntropyMagnetic Moment

Rotational Magnetic MomentMagnetic SusceptibilityNuclear Magnetic Resonance

SpectraFirst MomentsSecond MomentsDouble Quantum TransitionsChemical ShiftDouble ResonanceLine ShapeLine Width

- A 5 -

pro, rt;

PROPERTIES, PROCESSES AND PHENOMENA (CONT.)

Nuclear Spin "Spin CouplingNuclear Spin-Rotation InteractionNuclear Shielding ConstantsNuclear Spin Relaxation Time

FerromagnetismOverhauser Effect

Mass SpectraIonization and Appearance PotentialsIonization ProbabilityPartial Ionization Cross-sedtion

Mossbauer Spectra

Molecdlar StructureBond Distances and Bond AnglesIsomerismMolecular ShapeMolecular SizeSteric EffectsMoment of Inertia; Rotational Constants

Nuclear Properties (see also Nuclear Magnetic Resonance; Nuclear Quadrupole ResonanceNuclear Shielding ConstantsSpin Conversion, ortho-pareNuclear Spin Relaxation Time

Nuclide PropertiesAbundanceMassSpin

Optical PropertiesAnisotropy, OpticalBirefringenceDichroismDiffractionGouy FringesOptical RotationPhoton Effects

'Lifetime

PhotoconductionActivation Energy.

Quantum Yield, PhotoconductionPhotoeledtric Effect (includes photosensitivity)PhotoemissionPhotochemical Decomposition and Formation

Quantum Yield, PhotochemistryPhotoionizationMulti-Photon Processes

'Pleochroism

- A 6 -

PROPERTIES, PROCESSES AND PHENOMENA (CONTO

Reflectance; ReflectivityRefraction

Index of Refraction; Refractive IndexScattering Properties, Optical; Transmission Coefficients, Optical

Quantum Mechanical Properties

HamiltoniansSpin Hamiltonian

Symmetry PropertiesParityTime Reversal

Wave Functions and EigenfunctionsEigenfunctionsOrbital Angular Momentum Wave FunctionsOrthogonalized OrbitalsSpin Eigenfunctions

Wave Function Integrals and Matrix ElementsExpectation ValuesOverlap IntegralsTransition ProbabilitiesBond Resonance IntegralsOne-electron, One-center IntegralsOne-electron, Two-center IntegralsThree-center and Four-center Integrals

Radiation EffectsConductanceIon FormationIon YieldIonizationIonization EnergyIonization Probability; Ionization Cross-SectionRadiation Products

Stability. of Radiation ProductsTemperature Dependence, Radiation Effects

RadiochemistrySpontaneous Transmutation, Beta-DecayRadiative Neutron CaptureDecay SchemesIsomeric TransitionsPositronium Lifetime

Relaxation Time and RelaxationDissociation Relaxation TimeElectron Spin Resonance Relaxation TimeDielectric Relaxation TimeIonization Relaxation Time

-A7-

PROPERTIES, PROCESSES AND PHENOMENA (CONT.)

Nuclear Spin Relaxation TimeRelaxation Time SpectraRotational Relaxation TimeStructural Relaxation TimeVibrational Relaxation TimeThermal Relaxation TimeQuadrupole-Coupled RelaxationMagnetic Dipole Spin-Spin Relaxation

RotationCoriolis EffectsInternal RotationMolecular RotationRotational Spectra

FrequencyLine ShapeLine WidthRotational Constants; Moment of InertiaSelection RulesStark EffectZeeman EffectLambda DoublingIntensity

Nuclear Spin-Rotation InteractionRotation-Electron Spin InteractionRotation-Vibration InteractionRotational Relaxation TimeRotational-Vibronic Interaction

Solid State PropertiesCrystal Structure and Crystal Dynamics

Atom PositionCation DistributionDefectsLattice EnergyLattice ParametersLattice VibrationsMicrostructureCrystal Surfaces

Surface DistortionSurface Energy

Unit CellCrystal Growth

Rate of NucleationCrystal Spectra

Crystalline Field ParametersElectric and Magnetic Dipole TransitionsIrreducible RepresentationsIntensityFrequencyStark EffectTemperature Dependence of Spectra

Zeeman Effect

- A 8 -

PRCPERTIES, PROCESSES AND PHENOMENA (CONT.)

Optical Properties of Solids (see also Optical Properties)

Color CentersPhotoemissionPhotoeffectsReflectivity

Ele2tric and Magnetic Properties of SolidsCarrier MobilityIonic ConductivityElectron MobilityHolesIonic DiffusionPhotoconductivityPiezoelectricityPolarizabilityTransition from Semiconductor to Metallic State

Thermoelectric EffectsSeebeck CoefficientsTrap Depths

Transport PropertiesElectrical ConductivityThermal ConductivityThermal Diffusion CoefficientDiffusionViscoelastic Properties

Solutions (see also Fluid Properties)

Donnan Equilibrium ParameterReaction MechanismsStructure of SolutionsSolvent EffectsIonic MobilityCritical Properties

Spin PropertiesElectron Spin-Rotation interactionElectron Spin-Spin CouplingNuclear Spin-Spin CouplingSpin Conversion, ortho-paraNuclear Spin-Rotation InteractionSpin HamiltonianSpin-Orbit CouplingSpin SusceptibilityElectron Spin Relaxation TimeNuclear Spin Relaxation Time

Surface and Film Properties (see also Solid State Properties)

Accommodation CoefficientsSorption

AbsorptionAdsorptionChemisorptjonDesorption

Film ThicknessSurface Tension

- A 9 -

PROPERTIES, PROCESSES AND PHENOMENA (CONT.)

Thermodynamic Properties and Thermal Properties

Accommodation CoefficientsActivityCompressibilityCritical Properties

Critical PointDensityEnergy

Configurational EnergyEnergy of ActivationEnergy of Formation and DissociationEnergy of FusionEnergy of HydrationEnergy of Mixing

Energy of SolutionEnergy of TransitionEnergy of Vaporization

Energy of EvaporationEnergy of Sublimation

Zero-point EnergyEnthalpy

Enthalpy of ActivationEnthalpy of Formation and Dissociation

Enthalpy of FusionEnthalpy of HydrationEnthalpy of Mixing

Enthalpy of SolutionEnthalpy of TransitionEnthalpy of Vaporization

Enthalpy of EvaporationEnthalpy of Sublimation

EntropyEntropy of ActivationEntropy of Formation and Dissociation

Entropy of FusionEntropy of HydrationEntropy of Mixing

Entropy of SolutionEntropy of TransitionEntropy of Vaporization

Entropy of EvaporationEntropy of Sublimation

Equation of StateVirial Coefficients

Formation Constant; Association Constant

Free EnergyFree Energy of ActivationFree Energy of Formation and Dissociation

Free Energy of FusionFree Energy of HydrationFree Energy of Mixing

Free Energy of Solution

-A10-

PROPERTIES, PROCESSES AND PHENOMENA (CONT.

Free Energy of TransitionFree Energy of Vaporization

Free Energy of EvaporationFree Energy of Sublimation

Heat CapacityPartition FunctiOnsPhase TransitionPhase DiagramPressure

Partial PressureVapor Pressure

TemperatureThermal ConductivityThermal DiffusionThermal Expansion CoefficientVolume

Free VolumePartial Molar Volume

Work Function

Vibrational PropertiesRotation-Vibration InteractionVibrational EnergyVibrational CouplingVibrational Spectra

AnharmonicityForce ConstantsInfrared Spectra

IntensitiesRaman SpectraIntermolecular CouplingPotential Function; Potential ConstantsSelection Rules, Symmetry Classifications and Irreducible Representations

Torsional OscillationsPressure EffectsLine ShapeNormal CoordinatesFundamental Modes

X-ray Spectra

-All-

APPENDIX ACHEMICAL PHYSICS VOCABULARY

METHODS

Acoustics and UltrasonicsAtomic and Molecular Spectroscopy

Mass SpectroscopyTime-of-flight mass spectrometer

Mossbauer SpectroscopyNeutron DiffractionX-Ray DiffractionEmission SpectroscopyUltraviolet and Visible SpectroscopyInfrared and Near Infrared SpectroscopyRaman SpectroscopyFar Infrared SpectroscopyMicrowave Spectroscopy

Beam-maser Microwave SpectroscopyNon-resonant Microwave SpectroscopyElectron Paramagnetic ResonanceNuclear Magnetic ResonanceNuclear Quadrupole ResonanceX-Ray Spectroscopy

Beams.

Atomic BeamsElectron BeamsMolecular Beams

Chemical ProcessesChemical AnalysisChromatography

as

Ion ExchangeLiquid

Combustion and FlamesDetonation and Shock WavesElectrochemistry; PolarographyElectrolyte TheoryIsotope Effects; Isotope FractionationIsotope Exchange; Isotope SeparationKineticsPhotochemistry

Flash PhotolysisRadiation ChemistryRadiochemistry

Positronium ChemistryCrystal Field Theory

Electricity and MagnetismDielectric RelaxationElectrical MeasurementsElectromagnetic TheoryElectrostaticsMagnetic Weighing

-Al2-

METHODS (CONT.)

Electron MethodsElectron BeamsElectron DiffractionElectron Scattering; Electron ImpactElectron Swarm

Heat and Thermodynamic ProcessesCryoscopyTemperature MeasurementsThermal' Analysis

Classical ThermodynamicsStatistical Mechanics; Statistical ThermodynamicsQuantum Statistical MechanicsIrreversible Thermodynamics; Non-equilibrium Statistical Mechanics

Lasers, Masers, and Optical PumpingLigand Field TheoryLuminescence

Mathematical MethodsAnalytical GeometryDifferential EquationsGroup TheoryHilbert Space TheoryStatistics

Mechanics (classical)Microscopy

Electron MicroscopyField Emission Microscopy

Optical Microscopy

Nucleation

Optical Methods (Non-spectroscopic)InterferometryPolarimetryNon-linear optics (two-photon processes)Optical BirefringencePolarizationReflection

Quantum MechanicsQuantum mechanics, general theoryQuantum mechanics, methods and calculations

Density matrix methodsWave function methods

Approximation methodsPerturbation theory

time-dependenttime-independent

Variation theoryWKB

Group theoretical methods

A 13 -

METHODS (CONT.)

Ligand field theoryMolecular orbital calculations

LCAOSCFCIPPPsplit pelectron correlationHuckelMO theories including as well as electrons

Quantum mechanics, intermolecular interactions; 'scattering theory

Quantum electrodynamicsField theory

ScatteringElectron ScatteringLight Scattering

ElasticInelastic

Neutron ScatteringProton ScatteringScattering TheoryX-Ray Scattering

SorptionAbsorptionAdsorptionDesorption

Transport Processes (see also Statistical Mechanics)Collision Theory; Kinetic Theory of Gases

DiffusionEffusionHydrodynamicsThermal ConductionThermal DiffusionTranspirationTransport TheoryViscoelastic and Rheological Measurements

CalorimetersComputer ProgramsCountersDensitometersDilatometersDosimetersElectrodesKnudsen CellMagnetometersPressure Gauges; ManometersSpectrophotometersViscometers

DEVICES

- A 14 -

771

Absdi"wiLANOluiag:

APPENDIX ACHEMICAL PHYSICS VOCABULARY

OBJECTS

ParticlesSubnuclearElectronsNeutronsProtons

NucleusAtom

HotStableUnstable

MoleculeInorganicMetallo-organicOrganic

Transition-metal complexes and compoundsOctahedralTetrahedral

IonNegativePositive

CatalystsChelatesChromophoreClathratesDyesElectrolytesExcitonsFerroelectricsFree RadicalsimpuritiesInsulatorsLaser and Maser MaterialsMacromolecules and ProteinsMetalsPhotoconductorsPolymersSemiconductors

FluidsGases

IdealReal

LiquidsFluid Mixtures

Gas MixturesLiquid Mixtures and Solutions

Liquid CrystalsSolids

CrystalsSingle CrystalsPolycrystalline Materials

- A 15 -

L ffic 4-rfnori

4-.

,

OBJECTS (CONT.)

Thin FilmsMonolayersMultilayers

Solid MatrixFibersGlassesDispersions (colloids)

Solid SolutionsInterfacesSutfaces

Non-equilibrium systems and steady statesStationary StatesAcid-base systemsCharge-transfer complexesExcited statesIon-exchange systems (including proton transfer)Ion-molecule interactionsPolar mediaSinglet stateTriplet state

DipolesElectrodesOscillator systems

Harmonic oscillatorsAnharmonic oscillators

RotorsNon-rigidRigid

Spin systemsS4*

-n-particle systems (n>3)Three-particle systems,

fat cube

hard helixlong plateround random coilshort rodsoft spherethin square

disc

-A16-

4.11.111.mmimum

APPENDIX B

Analysis of CarrPurcell Spin-Echo NMR Experiments on Multiple-Spin Systems.I. The Effect of Homonuclear Coupling*

ADM ALLERITAND

Department of Chemistry, The Johns Hopkins University, Baltimore. Marylou(

(Received 26 August 1965)

The effect of homonuclear coupling in a molecule on CarrPurcell spin-echo (CPSE) nuclear magnetic

resonance experiments is investigated. A density-matrix approach is used to derive a general equation for

the CPSE train of multiple-spin molecules in the liquid state. This general equation predicts a CPSE train

modulated with one or more frequencies, whose relative amplitudes are, in general, not equal. Unmodulated

contributions may also arise. It is shown that the modulation frequencies and their relative amplitudes

are functions not only of the relative chemical shifts and coupling constants, but are strongly dependent

on the separation between the 1800 pulses, tip In addition, the modulation can always be eliminated by

making the pulse repetition rate, 1/10, large with respect to all the relative chemical shifts and coupling

constants. It is also shown that, for weak coupling, it is possible to derive simplified equations by neglecting

the nonsecular part of the coupling Hamiltonian, but this approximation is valid only wheniliit, is ofthe order of, or smaller than the relative chemical shifts.

Procedures for solving the general equation to obtain closed formulas for the CPSE train of a specific

system are discussed. Solutions for spin-} nuclei are treated in detail. Closed equations are derived for the

AB, Asti, and Aall systems, and they are used in some numerical calculations. Simplified weak-coupling

formulas are also derived for these systems, and their range of validity Is discussed.A very brief discussion of heteronuclear coupling is presented.

J. Chem. Plays. 1t1+, 1 (1966)

PropertySpin-spin couplingChemical shift

ObjectMoleculeLiquidSpin system =

MethodNuclear Magnetic Resonance

Density Matrix

J. Chem. Phys. .44, 1 (1966)

PropertySpin-spin couplingChemical shire

ObjectMoleculeLiquidSpin system>

MethodNuclear Magnetic ResonanceDensity Matrix

Theoretical

Theoretical

B 1 -

Molecular Orbital Theory for Octahedral and Tetrahedral Metal Complexes

HAROLD BASCLI, ARLEN VISTEI* AND HAM B. GRAY

The Department of Chemistry, Columbia University, New York, New York

(Received 4 May 1965)

Self-consistent charge and configuration (SCCC) molecular orbital calculations are reported for 32selected octahedral and tetrahedral first-row transition-metal complexes containing halide and chalco-genide ligands. It is found that for the range of metal oxidation states II through IV, chosen to fit theexperimental A, is a function of only the metal atomic number for constant F,. In the range of formalmetal oxidation numbers V through VII, F, is also a function of oxidation number.

Calculated and observed trends in covalency, A values, and first L--)M charge-transfer energies arecompared. The conclusion is drawn that the molecular orbital method, in its present formulation, gives areasonable account oCthe:ground states and low excited states in simple metal complexes.

J. Chem. Phys. 44, 10 (1966) Theoretical

PropertyCharge-transfer energyCovalence and ionic characterIonization potential

ObjectTransition-metal complexes - octahedral

MethodLigand field theory

J. Chem. Phys. 44, 10 (1966) Theoretical

PropertyCharge-transfer energyCovalence and ionic characterIonization potential

ObjectTransition-metal complexes - tetrahedral

MethodLigand field theory

- B 2 -

yi

Electronic Spectrum of (2, 2)Paracyclophane. II*

ARZA RON AND 0. SCI1NEPP

Department ofChemistry, Israel Institute of Technology, Haifa, Israel

(Received 16 July 1965)

The studies of the absorption and fluorescence spectra of single crystals of (2,2)paracyclophane in the

region 3300-3100 A reported in a previous paper have been extended. Well-characterized samples with the

(h140) developed crystal plane were used. In absorption two distinct spectra were obtained in the two polari-

zation components. The fluorescence was strongly polarized in one direction (parallel to the fourfold c axis)

and represents the mirror image of the equally polarized absorption component. It was concluded that

the observations prove conclusively that the differently polarized spectral components represent transi-

tions to two different electronic states, with an energy difference of 369 cm-1. The lowest-energy transition

certainly contains the 0-0 line and all available evidence supports the conclusion that also the second transi-

tion has allowed character. The only interpretation consistent with all observed features of the spectra is

as follows. The two observed states are the gerade dieter states (B2, and Bo in Du) being the out-of-phase

combinations of the Bs. and Bly benzene moiety states. The transitions have allowed character due to a

torsional distortion of the molecule in the excited state. The interpretation is fully consistent with theoretical

energy calculations.

J. Chem. Phys. 44, 19 (1966

PropertyLuminescence spectraElectronic spectraTorsional energy

ObjectCrystal, singleMolecule, organicExcited state

Experimental

C16116

MethodUltraviolet and visible spectroscopy

Densitometer

3100 - 3300 R.

-7 4

- B 3 -

FROM:ff

ERIC FACILITY

E 601

1735 EYE STREET, N. W.

WASHINGTON, 0. C. 20006