Monte Carlo simulations are presented for a coarse-grained model of real quadrupolar fluids. Molecules are represented by particles interacting with Lennard-Jones forces plus the thermally averaged quadrupole-quadrupole interaction. The properties discussed include the vapor-liquid coexistence curve, the vapor pressure along coexistence, and the surface tension. The full isotherms are also acce...

Atomic quadrupole moments and hyperfine constants of the metastable D3/2,5/2 states of Ca +, Sr+, Ba+, Yb+, and Hg+ are calculated by the multiconfiguration Dirac-Hartree-Fock and relativistic configuration-interaction methods. For Hg+, the configuration is 5d96s2. For the other ions, the configuration consists of a single d-electron outside a set of closed shells. Current interest in the quadr...

We present the results of an extended computational study of the electric and magnetic properties connected to Cotton-Mouton birefringences, on the trifluoro- and trichloroborides in the gas phase. The electric dipole polarizabilities, magnetizabilities, quadrupole moments, and higher-order hypersusceptibilities--expressed as quadratic and cubic frequency-dependent response functions--are compu...

Infrared spectroscopy is used to observe the orientational fine structure arising from ortho-H2 adsorbed at the primary site of the microporous framework MOF-5. The Q1(1) vibrational transition shows at least two symmetrically spaced fine structure bands on either side of the main band. These grow in relative intensity with increasing H2 concentration indicative of interacting H2 pairs. This in...