Theoretical Investigation on the Nuclear Quadrupole Interaction of CH₃Cl, CH₂Cl₂ and CHCl₃

Abstract

The nuclear quadrupole interaction of 3 5 C1 in C H 3 C1, C H 2 C12 and CHC13 has been studied theoretically by the H artree-Fock-R oothaan procedure. The influence of the crystal field on the nuclear quadrupole coupling constant is incorporated by the cluster approach and by using point charges that are consistent with the external potential.

Potential energy function for apatites

“…Partial charges in a crystalline environment derived from electronic structure theory are influenced by the 3D lattice periodicity. In this work, we applied the Madelung point charge embedded cluster-self consistent field (MPCEC-SCF) approximation 24 that has been successfully used to predict nuclear quadrupole interactions in chlorine-substituted methanes. By construction, this technique is ideally suited to optimise electrostatic potential-derived (PD) charges 25 for use in solid state MD simulations: Based on an idea by Sauer, 26 quantum-chemical calculations are applied to a small cluster representing a crystal fragment, embedded in an environment of a large number of point charges that, together with the cluster charges, are determined as to approximately represent the true Madelung potential anywhere in space.…”

Electric field gradient calculations forLixTiS2and comparison withLiBredow1, Heitjans2, Wilkening3 2004Phys. Rev. B926870View full textAdd to dashboardCite

“…Experimentally, the coupling of the electric field gradient and the quadrupole moment tensor, Q, of nuclei with spin quantum number I ജ 1 is accessible by nuclear magnetic resonance (NMR) techniques. [18][19][20] First-principles quantum-chemical investigations of quadrupolar interactions in solid systems are based on two kinds of models, the embedded cluster model [21][22][23] and the periodic supercell model, either based on plane-waves [24][25][26][27] or on atom-centered basis functions. [28][29][30] While periodic models take into account long-range electrostatic interactions in crystalline systems, the results obtained with model clusters strongly depend on their size and shape.…”