Crystals may be classified as either ionic or covalent by analogy with molecules . 与分子的情况一样，晶体也可以分为离子键型和共价键型。
2.
An ionic bond is characterized by the transfer of an electron from one atom to the other . 离子键的特点是一个电子可以从一个原子转移到另一个原子。
3.
Both ionic and covalent bonds arise from the tendency of atoms to attain this stable configuration of electrons . 离子键和共价键都是由于原子要达到这个稳定电子构型而形成的。
4.
The chains are held together by ionic bonds , whereas individual silica tetrahedrals bond together covalently 这些链状四面体组织由离子键束缚，而一个个单独的硅四面体却以共价键结合在一起。
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In recent years researchers have achieved better performance with compounds such as lithium borohydride , in which the metal atoms form weaker , ionic bonds with groups containing several hydrogen atoms 近年来，研究人员已经制作出效能更佳的复合物，例如硼氢化锂，在这种金属氢化物中，金属原子与氢原子团（由数个氢原子组成）之间，是以较弱的离子键键结。
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( c ) the total energy of manganate - oxides materials decreases after intercalation lithium . the electrovalent bond weakens and the covalent bond strengthen between manganese and oxygen due to ion polarization effect , which makes the spinel structure more stable ( 3 )对于锰系材料嵌锂后，体系总能量降低；锂离子的静电作用和极化作用，使锰氧之间的离子键成分减小，共价键成分增加，整个尖晶石骨架结构更加稳定。
7.
Organic - inorganic assembly layered perovskite - type materials integrate useful organic and inorganic characteristics on a molecular level . the inorganic component forms an extended framwork bound by strong covalent or ionic interactions , and the organic component is filled in which and thus the organic layer and inorganic layer are alternately stacked . the materials have unique properties such as electronic , optic and magnetic properties , and there has been great interest in studying them recently 层状类钙钛矿有机-无机分子组装材料在分子水平上结合了有机组分和无机组分的有益特性，无机组分通过强的共价键或离子键形成扩展的骨架，并将有机组分填入框架中形成有机层与无机层交替的结构，具有某些电学、光学、磁学特性，引起人们的研究兴趣。
