Hartree–Fock and Hartree–Fock–Slater electric field gradients (H2, CH4) and their symmetry mode derivatives (CH4)

Electric field gradients in the molecules H2 and CH4 are calculated by the Hartree–Fock and Hartree–Fock–Slater methods. In CH4, the derivatives of the electric field gradient with respect to the vibrational symmetry modes are determined. It is shown that one C–H stretch symmetry mode derivative is completely dominant. This derivative has recently been used to explain the quadrupole splittings found in the NMR spectra of the deuterated methanes dissolved in liquid crystals.