Conventional metallic bondings, both the classical model and the energy band model, are non-directional because all of the outer valence electrons of the atoms are shared commonly by all of the positive-ion cores (atoms without their valence electrons). However, Young's moduli of many metal crystals, which represent characteristics of bonding force, are very different according to the crystallographic directions, and also the metal crystals deform plastically with preferable slip planes and twin planes. They have different metallographic crystal structures at different temperatures in the allotropic phase transformations. It is remarkable as phenomenal evidence of crystallographic directionality, that the seed crystal in the liquid metal makes molten metal solidify in the same structure as itself. It is obvious that the conventional metallic bonding theory by electron gas clouds can not explain systematic and regular crystallization. Bonding in metal solids is not of the conventional energy-band model, but is composed of the regular three-dimensional crystallizing pi-bonding orbitals, and normal conduction electrons move from one crystallizing pi-bonding orbital to the next with the aid of electric potential field. Semiconductors have base atoms of three-dimensional crystallizing pi-bonding orbitals, where the conduction electrons are promoted from the covalent bondings to the pi-bonding orbitals by thermal vibration energy. The deficient atom sites in the three-dimensional crystallizing pi-bonding orbitals make superconductable thrown out electrons, which are evidenced from the Meissner, tunnelling and Josephson effects. The increased numbers of NOEs in side chain residues between proto-oncogenic and oncogenic forms of the neu protein might be caused by a packing of the atoms, in which the atoms have remaining valence electrons and make three-dimensional crystallizing pi-bonding orbitals. The oriented magnetic dipoles of flowing water molecules by static magnetic flux in blood vessels make planar crystals of oxygen atoms by the crystallizing pi-bonding, which produce periodic forces and activate water molecules. The catalytic action in chemical reaction is caused by crystallizing pi-bonding orbitals. (C) 1997 Elsevier Science S.A.
