Stability of two-dimensional BN-Si structures

Abstract

Two-dimensional (2D) BNSi2 has been recently proposed to be a viable candidate material with a graphene-like structure. We have carried out ab initio evolutionary ground state searches and uncovered a number of 2D structures in the (BN)xSi1−x pseudobinary system with considerably lower energies. Nevertheless, our formation energy analysis shows that none of these or previously proposed polymorphs are stable with respect to phase separation into 2D Si and BN. Examination of the related CSi, BNC2, and BNSi2 2D compounds indicates that the lack of miscibility in the last two systems is due to limited involvement of nitrogen electronic states in the covalent bonding.

Modeling of Si–B–N Sheets and Derivatives as a Potential Sorbent Material for the Adsorption of Li+ Ion and CO2 Gas Molecule

“…The bond lengths of all of the structures are summarized in Table 1, where the bond lengths of Si–Si, Si–B, Si–N, and B–N are consistent with previous results. 2,18,22 Especially, the experimentally reported bond length of B–N is 1.45 Å 24 and present investigation reports in Table 1 are exactly the same. The parameters such as the area and perimeter of the rings play a vital role in the adsorption mechanism.…”

“…These kinds of structures are theoretically reported previously. 22,23 To include more variety of Si–B–N combinations, the exotic motif has threefold coordinated atoms, and it is connected to pentagonal and octagonal rings as shown in Figure 1 (M4). The M4 structure is slightly bent (nonplanar) because the nonvalance silicon atoms in the defective rings have a stronger attractive nature that pulls the other atoms strongly toward it and creates the structural stress.…”

Few-body quantum method in a d-dimensional space

“…where R ext is the wave function without phase factor, and r is scaled as in Eq. (12). The maximum overlap of unity is obtained for b = b d and s = b z /b d .…”

“…In nuclei these deformations are never extreme because they arise as self-Email address: e.garrido@csic.es (E. Garrido) supported isolated structures without coupling to environment or other systems. This is in sharp contrast to cold atoms and molecules where external fields are used to confine systems into deformed and even all the way to extreme lower dimensions [9,10,11,12,13,14]. The rapid technical developments in conjunction with the qualitative change of properties have prompted a number of both theoretical and experimental investigations in one and two dimensions [15,16,17].…”

Feminicidio, impunidad o seguridad jurídica en la política criminal colombiana

“…Por consiguiente y validando otras teorías sobre el tema, se encuentra la planteada por el doctor Sandoval, quien establece que "los verdaderos problemas de la impunidad son a su vez corrupción" (Sandoval, 2016) y además que se tienen los "fenómenos de abuso" (Ibid., Sandoval) que resultan claros frente al desarrollo social de la impunidad, también es necesario aclarar que "la visión tradicional de la teoría de la democracia liberal retrata al ámbito privado como un sitio de sinergias, iniciativa y libertad" (Óp., Sandoval) estableciendo que es una situación que se presenta en el sector privado y en el sector público.…”