Calculation of Nuclear Magnetic Shielding in Hydrogen Molecule

摘要

The variation method for the calculation of nuclear magnetic shielding as described by Das and Bersohn Phys. Rev.104,849 (1956) has been shown to be justified on the basis of Rebane's Soviet Phys.hyphen;JETP11,694 (1960) more general considerations. This variation method has been employed to recalculate the proton magnetic shielding in the hydrogen molecule. The vector potential for the externally applied uniform magnetic fieldHis taken in the following form:Axxequiv;lpar;0,0,yHrpar;;thinsp;thinsp;Ayyequiv;lpar;0,0,minus;xHrpar;;thinsp;thinsp;andthinsp;Azzequiv;lpar;0,xH,0rpar;,where, for example,Axxstands for the vector potential whenHandmgr;(the proton magnetic moment) are both in thexdirection. The three quantities in the bracket are the three Cartesian components of the vectorA.It has been found that with this vector potential, a considerable portion of Ramsey's secondhyphen;order paramagnetic part can be calculated without considering the excited electronic states of the molecule.