“…Golding (300) has also calculated these effects for octahedral symmetry. Quadrupole interactions can originate from particle size effects and geometrical environment (68, [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] or induced by magnetic interactions as observed by Hoy et al (368, 369), and Gruzin et al (323). Relaxation and electron hopping can also produce changes in the quadrupole splitting (336).…”