CHEN CHUANG-TIAN. AN IONIC GROUPING THEORY OF THE ELECTRO-OPTICAI AND NON-LINEAR OPTICAL EFFECTS OF CRYSTALS (Ⅱ)——A THEORETICAL CALCULATION OF THE SECOND HARMONIC OPTICAL COEFFICIENTS OF THE LITHIUM IODATE CRYSTAL BASED ON A HIGHLY DEFORMED OXYGEN-OCTAHEDRA MODEL IJ. Acta Physica Sinica, 1977, 26(2): 124-132. DOI: 10.7498/aps.26.124