Search results for "Fig"
showing 10 items of 1359 documents
Analytic second derivatives for general coupled-cluster and configuration-interaction models.
2004
Analytic second derivatives of energy for general coupled-cluster (CC) and configuration-interaction (CI) methods have been implemented using string-based many-body algorithms. Wave functions truncated at an arbitrary excitation level are considered. The presented method is applied to the calculation of CC and CI harmonic frequencies and nuclear magnetic resonance chemical shifts up to the full CI level for some selected systems. The present benchmarks underline the importance of higher excitations in high-accuracy calculations.
The effect of triple excitations in coupled cluster calculations of frequency-dependent polarizabilities
1998
Abstract Frequency-dependent polarizabilities have been implemented within the CC3 model. Comparison with full configuration interaction results shows that the triple excitation effects included in CC3 lead to a significantly improved treatment for the dispersion of the polarizability of CH+. For the refractivity and polarizability anisotropy of N2, better agreement with experiment is found for the CC3 results than for those obtained with the coupled cluster singles and doubles model.
Full configuration-interaction and coupled-cluster calculations of the indirect spin–spin coupling constant of BH
2003
Abstract Full configuration-interaction calculations of the indirect spin–spin coupling constant of the BH molecule have been carried out in order to investigate the performance of various coupled-cluster (CC) methods in the treatment of electron-correlation effects, while the corresponding basis set convergence is analyzed in CC singles and doubles calculations. Assuming additivity of correlation and basis set effects, a theoretical estimate of 50.67 Hz is obtained for the 11 B 1 H spin–spin coupling constant.
Spin-orbit coupling constants from coupled-cluster response theory
2000
A scheme for the calculation of spin-orbit coupling constants using coupled-cluster (CC) electronic structure methods is described based on response-theory expressions for transition properties. An implementation is reported for singlet–triplet transitions within the coupled-cluster singles and doubles (CCSD) approximation. An atomic mean-field representation of the spin-orbit interaction is used to simplify the calculation of spin-orbit coupling constants. Sample calculations are presented for spin-orbit couplings for the 11Σ+→13Π transitions for BH and AlH and for the 11A′→13A″ and the 13A″→11A″ transitions for the silylenes HSiX, X=F, Cl, Br, and are compared to results obtained from ful…
La "lotta" alla criminalità organizzata
2020
Il contributo considera possibilità, limiti e condizioni dell’intervento del diritto penale nell’ampio fronte delle misure di contrasto al crimine organizzato. Si nega in primo luogo che tale forma di criminalità abbia una natura meramente temporanea e contingente, e che dunque la relativa normativa di contrasto possa confinarsi ad una pur grave, ma sempre circoscritta stagione dell’emergenza. Si procede quindi con una verifica della materia alla luce delle due teorie del diritto penale del nemico e del diritto penale di lotta. La conclusione nega l’utilizzabilità di formule così generali, per ragioni di ordine costituzionale e di caratteri costitutivi dell’intervento penale, e si pronuncia…
Older women's personal goals and exercise activity: an 8-year follow-up.
2013
This study investigated the associations of personal goals with exercise activity, as well as the relationships between exercise-related and other personal goals, among older women. Both cross-sectional and longitudinal designs were used with a sample of 308 women ages 66–79 at baseline. Women who reported exercise-related personal goals were 4 times as likely to report high exercise activity at baseline than those who did not report exercise-related goals. Longitudinal results were parallel. Goals related to cultural activities, as well as to busying oneself around the home, coincided with exercise-related goals, whereas goals related to own and other people’s health and independent living…
Spin Transitions in Iron(II) Complexes
1996
Iron(II) has the 3d6 outer electronic configuration and hence its octahedral complexes may be either high-spin or low-spin. The high-spin configuration, t 2g 4 e g 2 , is adopted when relatively weak-field ligands are coordinated while the low-spin, t 2g 6 e g 0 , is obtained when strong-field ligands are involved. In Oh symmetry the ground states are 5T2g and lA1g, for the high-spin and low-spin configurations, respectively. While in most iron(II) six-coordinate complexes the symmetry is lower than Oh, these designations are generally adopted in the following sections for convenience. [Fe(H2O)6]2+ and [Fe(en)3]2+ (en = ethylenediamine) are typical examples of high-spin complexes, while [Fe…
La catena del sapere
2017
Raccolta di studi per lo più concernenti contesti e testimonianze della cultura materiale, figurativa e architettonica della Sicilia greca, ma con ampliamenti d’orizzonte anche al mondo etrusco-italico e alla Grecia propria, condotti da punti di vista e con approcci diversificati.
Science and art from a transevolutionary perspective
2018
From its origins, the human species has manipulated not only the real world but also the figurative one. While that manipulative action of the human species over both worlds was critical for the survival of the species in the beginning of its evolution -now transevolution-, it is also true that in the subsequent culture those worlds have been approached by two trades with highly different conceptual bases, science and art. In this paper I hold the thesis that both trades are necessary to know how to be in the world as well as how to transform it in an appropriate way.
Le vin et l’éveil des sens. L’expérience du goût en partage
2016
International audience; Entre tous les éléments de la scène alimentaire, le vin offre sans conteste le plus large espace de représentation, de figuration. Tout fait sens en lui, prend valeur de signe, de figure : la terre et le terroir, le climat et la vigne, le travail en cave, la bouteille et l'étiquette, la table et les relations commensales, conviviales. Tout ce monde de signes, ce peuple de figures, donne saveur et valeur à nos émotions gustatives. Elles relèvent déjà d'un ordre sensoriel, du domaine de l'expertise mais avec des grilles et des normes de qualification, de catégorisation désormais entrées dans l'appréciation courante du vin lorsqu'on s'attarde sur sa dégustation. Au-delà…