Now showing items 51-60 of 140
Entire Phonon Spectrum of Molecular Crystals by the Localized Exciton Sideband Method: Naphthalene
(The American Institute of Physics, 1972-12-15)
The complete one‐phonon density‐of‐states of a molecular crystal can be mapped out by a carefully chosen exciton sideband involving a localized molecular internal excitation in a dilute isotopic mixed crystal. A theoretical ...
Molecular motions and [lambda] phase transition: Raman and far-ir studies of neat and isotopic mixed hexamethylbenzene crystal
(Elsevier, 1973)
Raman and far-IR studies of hexamethylbenzene (HMB) low temperature crystalline phases (neat and isotopic mixed) are presented. The Raman phonon spectrum changes drastically during the [lambda]-phase transition. Site ...
Microwave spectrum and structure of ethylene ozonide: Effects of large axes rotations in structure calculations
(Elsevier, 1976-03-30)
Rotational spectra for 14 isotopic species of ethylene ozonide have now been assigned. The consistency of the Kraitchman substitution structure was checked by calculating the Op---Op bond distance six ways; the values ...
Molecular structure of arsabenzene by gas-phase electron diffraction
(Elsevier, 1975-03)
Vapor-phase molecules of C5H5As were found, assuming C2v symmetry, to have the following structure parameters and uncertainties (2.5[sigma]): rg(C-As)= 1.850 +/- 0.003 A, rg(C2-C3) = 1.390 +/- 0.032 /rA, rg(C3-C4) = 1.401 ...
Excitons in ternary mixed molecular crystals: A prototype for the primary step of photosynthesis?
(Elsevier, 1976-03)
Exciton percolation, which has been demonstrated in synthetic ternary molecular alloys, is applied to photosynthetic light harvesting complexes. The resulting model ("substitutionally random") results in a predicted pigment ...
Contribution to the Theory of Frenkel Excitons in Disordered Molecular Crystals
(The American Institute of Physics, 1971-10-01)
In this paper, we discuss the Frenkel excitons in disordered molecular crystals. Most of our results can be generalized to cover electrons and phonons in other disordered systems as well. In particular, the relationship ...
Molecular mobilities in chromaffin granules magnetic field dependence of proton T1 relaxation times
(Elsevier, 1978-01-03)
The magnetic field dependence of the NMR spin-lattice relaxation time of water protons in intact bovine chromaffin vesicles has been studied over the range 1.00-23.49 kG. The T1 relaxation time shows a dispersion a t field ...
Relativistic corrections in a series of helium excited states
(Elsevier, 1978-05-15)
Relativistic corrections to order ([upsi]/c)2 are applied to the helium excited states 2 1,3P, 3 1,3D,..., 8 1,3K. Simple correlated open-shell wavefunctions are employed and the Breit operators H1 through H5 treated as ...
Structure and Conformation of Trimethylphosphine
(The American Institute of Physics, 1971-09-15)
Exciton states in organic alloys: Naphthalene-perdeuteronaphthalene
(Elsevier, 1975-11-15)
The lower band-edge energy of the first single exciton of naphthalene has been determined as a function of concentration in a C10H8/C10D8 alloy. Experimentally, the vibronic 0-512 fluorescence at 2 K and 1 cm-1 resolution ...