
A - Basics of electronic structure and Molecular bounding (Diatomic
... that the basis functions are nonorthogonal. Since the H+ 2 molecule has cylindrical symmetry the wave functions must be symmetric with respect to each atom, so this result is not surprising. The two eigenfunctions ϕ1 and ϕ2 are the odd and even combinations of the Slater orbitals, with symmetries σg ...
... that the basis functions are nonorthogonal. Since the H+ 2 molecule has cylindrical symmetry the wave functions must be symmetric with respect to each atom, so this result is not surprising. The two eigenfunctions ϕ1 and ϕ2 are the odd and even combinations of the Slater orbitals, with symmetries σg ...
Packing and Molecular Orientation of Alkanethiol Monolayers on
... Packing and Orientation of Alkanethiol Monolayers At lattice spacings less than about 4.8 A, however, it is not possible for the "racheting effect" to establish this special interlocking. Figure 7 shows how the best interaction energy (at the best tilt for this spacing) varies as a function of the ...
... Packing and Orientation of Alkanethiol Monolayers At lattice spacings less than about 4.8 A, however, it is not possible for the "racheting effect" to establish this special interlocking. Figure 7 shows how the best interaction energy (at the best tilt for this spacing) varies as a function of the ...
Phonon-mediated nuclear spin relaxation of H2O trapped in Ar matrix
... the temperature where an interstellar medium was formed [1]. However, recent investigations have revealed that NSC of H2O proceeds much faster in condensed systems [4,5]. Thus, interest in the NSC mechanism and channels is getting greater. In the present work, we devised a theoretical model of the p ...
... the temperature where an interstellar medium was formed [1]. However, recent investigations have revealed that NSC of H2O proceeds much faster in condensed systems [4,5]. Thus, interest in the NSC mechanism and channels is getting greater. In the present work, we devised a theoretical model of the p ...
The Dance of Molecules - American Chemical Society
... procedure Heisenberg used in fabricating quantum mechanics. This connects the quantum Hamiltonian with a classical form, which can be visualized with classical images of atomic motion. This semiclassical picture is not gotten immediately in terms of the atomic positions and velocities, which constit ...
... procedure Heisenberg used in fabricating quantum mechanics. This connects the quantum Hamiltonian with a classical form, which can be visualized with classical images of atomic motion. This semiclassical picture is not gotten immediately in terms of the atomic positions and velocities, which constit ...
Molecular-Fluorescence Enhancement via Blue
... the absorption of MC molecules. Along with the quenching of scattering from AuNRs, the blue-shifted PIRET enhances the fluorescence of nearby molecules. On the basis of the fluorescence enhancement, we conclude that AuNRs can be used as donors with clear advantages to excite the fluorescence of molecul ...
... the absorption of MC molecules. Along with the quenching of scattering from AuNRs, the blue-shifted PIRET enhances the fluorescence of nearby molecules. On the basis of the fluorescence enhancement, we conclude that AuNRs can be used as donors with clear advantages to excite the fluorescence of molecul ...
Electron Induced Fluorescence Spectra of Methane
... Figure 4. The values are in arbitrary units, however, the cross sections can be compared with each other. The threshold energies for particular dissociative excitation reactions were evaluated from the relative cross sections and are presented in the Table 1. They represent the superposition of mini ...
... Figure 4. The values are in arbitrary units, however, the cross sections can be compared with each other. The threshold energies for particular dissociative excitation reactions were evaluated from the relative cross sections and are presented in the Table 1. They represent the superposition of mini ...
A Quantum Mechanical Discussion of Orientation of Substituents in
... for the different kinds of atoms with which we will deal later, but we have not been able to arrive a t any mry consistent figures. Our procedure was to determine the values which would bring the calculated resonance energies into agreement with the empirical ones. The figures obtained in this way a ...
... for the different kinds of atoms with which we will deal later, but we have not been able to arrive a t any mry consistent figures. Our procedure was to determine the values which would bring the calculated resonance energies into agreement with the empirical ones. The figures obtained in this way a ...
Stochastic mechanism of excitation of molecules that interact with
... molecule into the region of the high-lying level is always accompanied by an increase of the self-consistent radiation field. The maximum values of $(t) greatly exceed in this case the eXterna.1-field amplitude E, (curve 1 in Fig. 5). In the case when the amplitude of the selfconsistent field in the ...
... molecule into the region of the high-lying level is always accompanied by an increase of the self-consistent radiation field. The maximum values of $(t) greatly exceed in this case the eXterna.1-field amplitude E, (curve 1 in Fig. 5). In the case when the amplitude of the selfconsistent field in the ...
Chapter 11 Angular Momentum
... Describe how astronauts floating in space can move their arms to turn upside down? Or turn around to face the opposite direction? ...
... Describe how astronauts floating in space can move their arms to turn upside down? Or turn around to face the opposite direction? ...
Exercises – Chapter 2
... 1. The chairs in an auditorium aren’t all facing the same direction. How could you describe their angular positions in terms of a reference orientation and a rotation? E.1 ...
... 1. The chairs in an auditorium aren’t all facing the same direction. How could you describe their angular positions in terms of a reference orientation and a rotation? E.1 ...
Rotational spectroscopy

Rotational spectroscopy is concerned with the measurement of the energies of transitions between quantized rotational states of molecules in the gas phase. The spectra of polar molecules can be measured in absorption or emission by microwave spectroscopy or by far infrared spectroscopy. The rotational spectra of non-polar molecules cannot be observed by those methods, but can be observed and measured by Raman spectroscopy. Rotational spectroscopy is sometimes referred to as pure rotational spectroscopy to distinguish it from rotational-vibrational spectroscopy where changes in rotational energy occur together with changes in vibrational energy, and also from ro-vibronic spectroscopy (or just vibronic spectroscopy) where rotational, vibrational and electronic energy changes occur simultaneously.For rotational spectroscopy, molecules are classified according to symmetry into spherical top, linear and symmetric top; analytical expressions can be derived for the rotational energy terms of these molecules. Analytical expressions can be derived for the fourth category, asymmetric top, for rotational levels up to J=3, but higher energy levels need to be determined using numerical methods. The rotational energies are derived theoretically by considering the molecules to be rigid rotors and then applying extra terms to account for centrifugal distortion, fine structure, hyperfine structure and Coriolis coupling. Fitting the spectra to the theoretical expressions gives numerical values of the angular moments of inertia from which very precise values of molecular bond lengths and angles can be derived in favorable cases. In the presence of an electrostatic field there is Stark splitting which allows molecular electric dipole moments to be determined.An important application of rotational spectroscopy is in exploration of the chemical composition of the interstellar medium using radio telescopes.