Relativistic and electron correlation effects on the calculation of NMR parameters in MX (M = Cu, Ag, Au; X = F, Cl, Br, I)

A. F. MALDONADO; ALBEIRO RESTREPO; EDISON FLOREZ; YULY CHAMORRO; G. A. AUCAR; JORGE DAVID

Bogotá

Encuentro; El VI Encuentro Nacional de Químicos Teóricos y Computacionales; 2016

Universidad Nacional de Colombia

Accurate calculations of NMR parameters, nuclear magnetic shieldings σ(M), σ(X), and indirect spin-spin J-coupling constant J(M−X) of group-11 metal halides MX (M = Cu, Ag, Au; X = H, F, Cl, Br, I), were carried out with relativistic and nonrelativistic theoretical schemes. Significant differences due to relativistic effects are observed on NMR parameters inthese systems. And an out of trend value for σ(Au) is found in AuF. It was previously suggested that such unexpected large value is an artifact originated in the appearance of quasi instabilities. Calculations of σ(F) and J(Au-F) in the same molecular systems also present very large values. We applied the polarization propagator formalism at the PZOA, RPA and SOPPA levels in order to analyze the quasi instabilities problem in this system as well as the electron correlation effects in the relativistic and nonrelativistic calculations on NMR parameters in MX. We found that the relativistic and electron correlation effects can not be treated independently.