Theoretical Studies of B₂Li_n (n = 1−4)

Abstract

Structures and energies of the binary B2Li n (n = 1−4) clusters are predicted with the HF, MP2, and B3LYP methods using the 6-31G(d) basis set, including energy evaluations at G2MP2 and CBS-Q and the larger 6-311+G(2d) basis set for B3LYP. All systems except B2Li4 are also computed with the CASSCF method because of spin contamination for several of the open-shell systems. These were followed by energy evaluations with multiconfigurational perturbation theory. The global B2Li minimum has a C 2 v triangular form of which the 2B1 state is 13 kcal/mol more stable than the 2A1 state. A bent double Li-bridged structure (C 2 v ) is the global B2Li2 minimum with a 2.0 kcal/mol inversion barrier. The global minimum for B2Li3 is a triple Li-bridged propellane-like structure (D 3 h ), and for B2Li4 it is the quadruple Li-bridged structure (D 4 h ). All these structure have a high degree of ionicity, but in B2Li4 stabilization through LiLi interactions also become important. Structural patterns for the isomers of these clusters are examined. Cohesive energies (B2Li n → B2 + Li n ) and Li and Li2 elimination energies are analyzed in terms of cluster stabilities.

Theoretical Investigation on Molecular Structure and Electronic Properties of BxLiy Cluster for Lithium-Ion Batteries with Quantum ESPRESSO Program

“…Density of state (DOS) and band structures are collected in Figures 8 and 9. When our results are compared with the well-studied clusters by Nguyen et al [23], Srinivas et al [34] and Ying Li et al [12], we can conclude that our calculations are correct and compatible. The calculated bond length of BLi is 2.141 Å at the QCISD (2.174 Å at the CCSD (T)).…”

“…The B-B bond vibrational stretching frequency is 1118 cm −1 for B 2 Li and 1014 cm −1 for B 2 at B3LYP. Total energy of B 2 Li is −56.56928 au at HF (−56.72242 au at MP2, −56.99109 au at B3LYP and −56.72824 au at CASSCF), as shown by Srinivas et al [ 34 ]. B 2 Li second isomer is made up of two boron atoms and one lithium atom with a triangular geometric structure, and the angles of this molecule are 69.56°, 69.73° and 40.71°.…”

“…The B-Li average distances of B 2 Li 2 second isomer are 2.107 Å at B3LYP, 2.137 Å at MP2, 2.135 Å at HF and 2.142 Å at CASSCF. The total energy of B 2 Li 2 second isomer is −64.05724 au at HF (−64.20792 au at MP2, −64.54499 au at B3LYP and −64.11602 au at CASSCF), as shown by Srinivas et al[34]. B 2 Li 2 second isomer is formed with three bonds, which are two boron-lithium bonds and one bond of B-B atoms.…”

Quantum Mechanical Design and Structure of the Li@B10H14Basket with a Remarkably Enhanced Electro-Optical Response

“…Compounds of boranes and borides indeed have spanned a large area of chemistry due to their aesthetically appealing structures and unique bonding features and the formation of cages and clusters . Among the borides, lithium borides have been extensively studied and showed that the lithium atom preferably forms a bridge around the central B−B bond .…”