Vibration and two-photon absorption

The rigorous and transparent treatment of the effects of nuclear vibrational motion in two-photon absorption (TPA) was discussed. Perturbation formula for diatomic molecules were developed and applied to the X¹Σ+–A¹Π transition in CO. The analysis showed that the vibrations played an important role in TPA, just as their role in the calculation of conventional nonlinear optical (NLO) hyperpolarizabilities

Additional compact formulas for vibrational dynamic dipole polarizabilities and hyperpolarizabilities

Compact expressions, complete through second order in electrical and/or mechanical anharmonicity, are given for the dynamic dipole vibrational polarizability and dynamic first and second vibrational hyperpolarizabilities. Certain contributions not previously formulated are now included

Simple finite field method for calculation of static and dynamic vibrational hyperpolarizabilities: curvature contributions

In the static field limit, the vibrational hyperpolarizability consists of two contributions due to: (1) the shift in the equilibrium geometry (known as nuclear relaxation), and (2) the change in the shape of the potential energy surface (known as curvature). Simple finite field methods have previously been developed for evaluating these static field contributions and also for determining the effect of nuclear relaxation on dynamic vibrational hyperpolarizabilities in the infinite frequency approximation. In this paper the finite field approach is extended to include, within the infinite frequency approximation, the effect of curvature on the major dynamic nonlinear optical processes

Calculation of Franck-Condon factors including anharmonicity: simulation of the C2 H4+ X̃2B 3u←C2 H4X̃1 Ag band in the photoelectron spectrum of ethylene

Our new simple method for calculating accurate Franck-Condon factors including nondiagonal (i.e., mode-mode) anharmonic coupling is used to simulate the C2H4+X2B 3u←C2H4X̃1 Ag band in the photoelectron spectrum. An improved vibrational basis set truncation algorithm, which permits very efficient computations, is employed. Because the torsional mode is highly anharmonic it is separated from the other modes and treated exactly. All other modes are treated through the second-order perturbation theory. The perturbation-theory corrections are significant and lead to a good agreement with experiment, although the separability assumption for torsion causes the C2 D4 results to be not as good as those for C2 H4. A variational formulation to overcome this circumstance, and deal with large anharmonicities in general, is suggested

A comparative analysis of two methods for the calculation of electric-field-induced perturbations to molecular vibration

Two common methods of accounting for electric-field-induced perturbations to molecular vibration are analyzed and compared. The first method is based on a perturbation-theoretic treatment and the second on a finite-field treatment. The relationship between the two, which is not immediately apparent, is made by developing an algebraic formalism for the latter. Some of the higher-order terms in this development are documented here for the first time. As well as considering vibrational dipole polarizabilities and hyperpolarizabilities, we also make mention of the vibrational Stark effec

Variational calculation of vibrational linear and nonlinear optical properties

A variational approach for reliably calculating vibrational linear and nonlinear optical properties of molecules with large electrical and/or mechanical anharmonicity is introduced. This approach utilizes a self-consistent solution of the vibrational Schrödinger equation for the complete field-dependent potential-energy surface and, then, adds higher-level vibrational correlation corrections as desired. An initial application is made to static properties for three molecules of widely varying anharmonicity using the lowest-level vibrational correlation treatment (i.e., vibrational Møller-Plesset perturbation theory). Our results indicate when the conventional Bishop-Kirtman perturbation method can be expected to break down and when high-level vibrational correlation methods are likely to be required. Future improvements and extensions are discussed

La Reforma Catòlica a la muntanya catalana a través de les visites pastorals: els bisbats de Girona i Vic (1587-1800)

La present tesi vol explicar la implantació de la Reforma Catòlica en una sèrie de parròquies rurals dels bisbats de Girona (valls de Ridaura, Bas, Hostoles i Amer) i Vic (El Collsacabra i les valls de Susqueda i Sau), entre 1587 i 1800, des dels bisbes posttrentins Jaume Caçador i Pedro Jaime als il·lustrats Tomàs de Lorenzana i Francisco de Veyan. La documentació principal són les sèries de les visites pastorals conservades a l'Arxiu Diocesà de Girona i l'Arxiu Episcopal de Vic; paral·lelament, s'ha reforçat amb documentació parroquial (llibres sagramentals, consuetes, llibres d'obra i confraries), protocols notarials (notaries de Rupit, Sant Feliu de Pallerols, El Mallol i Amer) i impresos episcopals. Els manaments de les visites pastorals s'han contrastat, amb semblances i diferències, amb els decrets del concili de Trento, de les constitucions provincials tarraconenses i les sinodals gironines i vigatanes, i amb les evidències artístiques, arquitectòniques i arqueològiques. Tots ells han servit per demostrar la lentitud en la implantació del programa tridentí, que s'assoleix, de fet, amb força retard (ben entrat el segle XVIII).

Parròquia i societat rural al Bisbat de Girona, segles XIII i XIV

La parròquia, poc valorada per la historiografia medieval, fou una la institució fonamental per a l'ordenació de la societat rural del bisbat de Girona entre els segles X i XIV. Constituïa un territori ben delimitat, els habitants del qual rebien els sagraments eclesiàstics dels clergues que regien l'església i, a través de l'obreria i dels obrers, participaven en la gestió del temple i de la seva economia. La parròquia va incidir directament en l'ordenació del poblament rural a través tant dels nuclis eclesials o "celleres" com dels masos dispersos pel terme d'una parròquia. A més, la parròquia era una important font de rendes: a través de la documentació generada pel bisbe de Girona, el delme era una renda en mans, sobretot, de senyors feudals, cavallers i importants institucions eclesiàstiques; els clergues parroquials només rebien les primícies i altres drets de menor valor. Finalment, la parròquia contribuí enormement a la configuració de les comunitats rurals de bona part del bisbat de Girona.