Premium
Calculation of magnetic properties of HF, H 2 O, NH 3 , and CH 4 molecules using a longitudinal gauge for the vector potential
Author(s) -
Ferraro M. B.,
Caputo M. C.,
Béccar Varela M. P.,
Lazzeretti P.
Publication year - 1998
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/(sici)1097-461x(1998)66:1<31::aid-qua4>3.0.co;2-0
Subject(s) - diamagnetism , mathematical descriptions of the electromagnetic field , physics , gauge (firearms) , tensor (intrinsic definition) , electromagnetic shielding , gauge theory , diagonal , lorenz gauge condition , vector potential , quantum mechanics , magnetic monopole , mathematical physics , quantum electrodynamics , hamiltonian lattice gauge theory , condensed matter physics , magnetic field , gauge anomaly , mathematics , geometry , archaeology , history
A transformation of the transverse Coulomb vector potential was implemented to calculate molecular magnetic properties via the random‐phase approximation (RPA) within the framework of a “longitudinal gauge.” In this gauge, the diamagnetic contribution to magnetic susceptibility is a tensor with equal diagonal components as in atoms, irrespective of molecular symmetry, whereas diagonal and average diamagnetic contributions to the nuclear magnetic shielding are the same as in the Coulomb gauge. Near‐Hartree–Fock magnetic susceptibility and nuclear magnetic shielding tensors were evaluated for a set of small molecules, HF, H 2 O, NH 3 , and CH 4 , employing extended Gaussian basis sets. The peculiar features of the longitudinal gauge, and the fulfillment of a series of sum rules involving the virial operator, which must be satisfied to guarantee gauge invariance of total magnetic tensors, were exploited to check the degree of convergence of theoretical values and to estimate the corresponding Hartree–Fock limit for the properties. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 66 : 31–45, 1998