Electric quadrupole polarizabilities of nuclear magnetic shielding in some small molecules

• Autores: Ferraro, M.B.; Caputo, M.C.; Pagola, G.I.; Lazzeretti, P.
• Año de publicación: 2008
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: J Chem Phys 2008;128(4)
• Materia: Approximation theory; Computational methods; Current density; Electric field effects; Mathematical transformations; Polarization; Quantum theory; Electric quadrupole polarizabilities; Nuclear magnetic shielding; Magnetic shielding
• Institución: Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales

Computational procedures, based on (i) the Ramsey common origin approach and (ii) the continuous transformation of the origin of the quantum mechanical current density-diamagnetic zero (CTOCD-DZ), were applied at the Hartree-Fock level to determine electric quadrupole polarizabilities of nuclear magnetic shielding for molecules in the presence of a nonuniform electric field with a uniform gradient. The quadrupole polarizabilities depend on the origin of the coordinate system, but values of the magnetic field induced at a reference nucleus, determined via the CTOCD-DZ approach, are origin independent for any calculations relying on the algebraic approximation, irrespective of size and quality of the (gaugeless) basis set employed. On the other hand, theoretical estimates of the induced magnetic field obtained by single-origin methods are translationally invariant only in the limit of complete basis sets. Calculations of electric quadrupole polarizabilities of nuclear magnetic shielding are reported for H2, HF, H2 O, N H3, and C H4 molecules. © 2008 American Institute of Physics.
Fil:Ferraro, M.B. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Caputo, M.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.
Fil:Pagola, G.I. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.