关于CO2的原子晶体的疑问

     《Science》说高压下CO₂变成SiO₂型的原子晶体，变成原子晶体我没意见，不过是SiO₂型，我就觉得奇怪了。
       SiO₂的∠Si—O—Si=180°显然其中的O取sp杂化，还剩两个p轨道和Si的3d轨道形成d-pπ键。Si可以搞d-pπ键，C就不行了，原子晶体的CO₂中的O只能取sp³杂化。
       依我之见：原子晶体的CO₂取SiS₂型比取SiO₂型更为合理，至少键角正常点。不知各位有何意见？是《Science》误记，我的分析有错，还是理论不够完善？

你确定Science 上说高压下CO₂中C-O-C 的键角是180度了吗？ SiO₂有很多晶型的，绝大部分Si-O-Si 的键角（比如常见的石英）都不是180度，只有磷石英Si-O-Si 的键角是180度。
这是我查到的，
http://www.esrf.eu/UsersAndScience/Publications/Highlights/1999/chemistry/polyco2.html
"above 35 GPa and 1800 K, highly strained CO2-III transforms into a new phase CO2-V that can be quenched at ambient temperature (Figure 39c). It clearly shows that the texture in the transformed area is distinct from that in a non-transformed area. In this study, the crystal structure of CO2-V has been found to be orthorhombic (P212121), analogous to SiO2 tridymite (a distorted high temperature phase of ß-quartz). Each carbon atom is bonded to four oxygen atoms at a carbon-oxygen distance of 1.36 Å at 40 GPa and an O-C-O angle of 110°. These CO4 tetrahedral units share their corner oxygen atoms to form a layered structure in the ab-plane; whereas, the apices of the tetrahedra are connected through oxygen atoms along the c-axis (Figure 40). This interconnected layer structure of tetrahedra results in a C-O-C angle of 130°, substantially smaller than those of SiO2 tridymites 174-180° or of quartz 145°. Such rigidity in the C-O-C angles may reflect the fact that oxygen atoms in CO2-V are more tightly bound than in SiO2 and result in a higher covalence and bulk modulus for CO2-V than for any of the SiO2 polymorphs. In fact, we found that the bulk modulus of CO2-V is about 362 GPa, substantially higher than SiO2-quartz (37 GPa) and even stishovite (310 GPa). It is nearly the same value with cubic-BN (369 GPa) and thus could be a good candidate for a superhard polymer."
大意是说，30GPa 高压下，CO2 的晶型与磷石英类似，但C-O-C 的键角是130度，显著地比Si-O-Si 在磷石英（174度～180度）以及石英（145度）的键角小。

感谢Cosmology，SiO2的∠Si—O—Si不全是180°我是第一次知道。
《Science》没说∠C—O—C=180°，是我孤陋寡闻，只知道∠Si—O—Si的180°，于是推测的……

路过长见识了