the electric quadrupole, hexadecapole moments, energy (kjmol -1) for some armchair polyhex carbon nanotubes tuvc6[2p,q] are performed by beck-lee-yang-parr [b3lyp] on 3-21g basis set using the standard procedure indices gaussian 98, then the padmakar-ivan (pi) index of tuvc6[2p,q] nanotubes in the terms of their circumference (2p) and lengh (q) is calculated and the relationships between the pa...

Relativistic formulas for the electric quadrupole moment of a hydrogenlike atom, induced by the hyperfine interaction, are derived for ns and np1/2 states. Both the magnetic dipole and electric quadrupole hyperfine interactions are taken into account. The formulas are valid for ions with arbitrary nuclear charge and spin. The induced quadrupole moment is compared with the nuclear quadrupole mom...

Relativistic formulas for the electric quadrupole moment of a hydrogenlike atom, induced by the hyperfine interaction, are derived for ns and np1/2 states. Both the magnetic dipole and electric quadrupole hyperfine interactions are taken into account. The formulas are valid for ions with arbitrary nuclear charge and spin. The induced quadrupole moment is compared with the nuclear quadrupole mom...

The nuclear quadrupole moment of In has been determined by combining the experimental nuclear quadrupole coupling constants and electric field gradients, calculated at the four-component CCSD~T! level of theory, of four indium halides. Our recommended value for the nuclear quadrupole moment of In is 770~8! millibarn. A basis set study at the Dirac–Hartree–Fock level shows a slow convergence of ...

The effect of relativity on the properties of the interhalogens ClF, BrF, BrCl, IF, IBr, and IBr is studied by comparing relativistic and nonrelativistic calculations. Bond lengths, harmonic frequencies, and dissociation energies show that the bond is weakened in the relativistic formalism. Relativity increases the electric dipole moment whereas the electric quadrupole moment and dipole polariz...

We consider a Dirac one-electron atom placed in a weak, static, uniform magnetic field. We show that, to the first order in the strength B of the perturbing field, the only electric multipole moment induced by the field in the ground state of the atom is the quadrupole one. Using the Sturmian expansion of the generalized Dirac–Coulomb Green function [R. Szmytkowski, J. Phys. B 30 (1997) 825; er...

The electric quadrupole coupling constant of the ground state of 37K(Iπ = 3/2+, T1/2 = 1.22 s) in a tetragonal KH2PO4 single crystal was measured to be |eqQ/h| = 2.99± 0.07 MHz using the β-ray detecting nuclear quadrupole resonance technique. The electric quadrupole moment of 37K was determined to be |Q(37K)| = 10.6 ± 0.4 efm2, where the known electric quadrupole coupling constant of stable 39K...