The concept of "spintronics" has attracted considerable scientific interest. In recent years, it has triggered a revolution in computer science, information science and other fields (1-4). "Semi-metal" data, a new compound whose current can be completely spin-polarized, has always been regarded as a promising spin-electron application theorem with metallic properties, which locates the electron spin direction and semiconductor or insulation properties as other rotations. In view of the potential of this property, in the design of spin-based electronics, since the theoretical prediction of De Grut, NiMnSb has shown semi-metallic properties in 1983 [5]. This semi-metallic behavior has been reported in three-dimensional materials, such as manganese perovskite [6] sphalerite (ZB) (such as CrAs and CrSb ZB structures, Fe3O4 and CrO2[6]). Interestingly, the semi-metallic behavior is predicted, and the nanoribbon two-dimensional graphene [7] in the external electric field opens up a new path for exploring nano-scale spintronics.

One challenge is the application of nano-debris technology to find the one-dimensional structure of semi-metal behavior. In this respect, Xiang [8] and Maslyuk[9] have independent one-dimensional organometallic manganese-and vanadium-benzene nanowires, which have semi-metallic display properties. One attraction is that carbon nanotubes with finite twists and turns have been proved to have semi-metallic behavior in electric field [10- 14]. In addition, recent research shows that semimetallicity may lead to functionalized boron nitride (1 billion dollars) systems, such as completely exposed nanobelts (15) and carbon nanotubes filled with nickel clusters [16].

In this letter, we put forward another strategy in theory, and realized tortuous carbon nanotubes in small molecules (including any, NO2 and O2) through simple semi-metallic behavior and unpaired electrons. The advantages of this strategy are: (1) the structural integrity of CNT can be well maintained, and (2) the encapsulated small molecules are stable and easy to handle. As far as we know, there have been reports on this issue without prior theoretical research.