In recent years, inorganic nanotubular systems have attracted considerable attention due to their unique phisico-chemical properties and thermal stabilities [1]. Although boron- phosphide nanotubes (BPNTs) have not been synthesized and their thermodynamic stability have not been reported so far, they have been the subject of considerable theoretical investigations [2,3]. The importance of BPNTs was attributed to the promising electrical, mechanical and thermal properties of crystalline zinc-blend structure of BP in one hand and the known similarity between the electronic properties of BP and silicon carbide (SiC) on the other [4]. In most cases, a heteroatom doped form of BPNTs was investigated and the properties of pristine BPNTs have been less studied [5]. In particular, the dependence of structural and electronic properties of BPNTs on the diameter and chirality, which is the subject of the present study, has not been investigated so far. Especially, we are interested in knowing whether, like the other tubular structures composed of elements of groups three (III) and five (V) of the periodic table, the electronic and structural properties of BPNTs is independent of the diameter and chirality of tube.
