M. Cattani

Convergent calculations for electron impact broadening and shift of neutral helium lines

Abstract Using the convergent semiclassical method, we have calculated the electronic widths and shifts of 42 neutral He lines for an electronic density of 1016/cm3 and T = 5000, 10,000, 20,000, and 40,000 K. To account of ions effects, we have calculated the Stark parameter A and parameter R.

Self-broadening of the ammonia inversion lines

Abstract We improve the theoretical approach developed by Lin et al. to explain the self-broadening of the ammonia inversion lines with J = K . Our theoretical predictions are compared with the experimental results of Legan et al. , Hewitt and Parsons, Hewitt, and Gierszal et al. A good agreement is found between theory and experiment.

Environment racemization: A two-level approach

Abstract A two-level quantum-mechanical approach is developed in order to explain how racemization depends on the interaction of the active molecule with the environment. Relevant physical parameters for the molecules and the optically-active sample are defined. Our predictions are applied to (a) dilute gases and (b) dense gases, liquids or solids.

Collisional racemization and weak neutral current

Abstract We calculate in detail the collisional racemization rate for a dilute gas. Our predictions can be used to investigate the action of weak forces in molecular systems.

Self-broadening of the ammonia inversion spectrum

Abstract We show that self-broadening of the ammonia inversion lines with J = K can be explained by taking account of the rotational resonance effect.

Racemization produced by elastic and inelastic molecular collisions in dilute gases

Abstract A simple many level model is developed to estimate the racemization produced by inelastic molecular collisions in dilute gases. The racemization due to elastic and inelastic collisions are compared.

Collisional racemization in dilute gases

Abstract A two-level approach is developed to explain the racemization in dilute gases produced both by natural tunnelling and by random collisional effects.

Racemization and weak interactions: A two-level approach

Abstract Assuming the active molecules as a two-level system, we investigate how the environment racemization depends on the effect of weak neutral currents. We analyse in detail racemization in dilute gases.

Collision shifting in the ammonia inversion spectrum

Abstract The shift parameters for self-broadened lines in the ammonia inversion spectrum have been calculated using the convergent approach of Cattani. Good agreement is found between theory and experiment.

Tunneling racemization in dense gases and liquids

Abstract We calculate the racemization in dense gases and liquids produced both by natural tunneling and by random binary interactions between active and perturbing molecules.