Structures and Stabilities of Alkaline Earth Metal Oxide Nanoclusters: A DFT Study

Table 5

Bond lengths (Å) and binding energies (eV) per MgO unit for different stoichiometries of (MO)𝑛.

MO	Number of units	Preferred structure	Binding energy; per molecule	𝑅
MgO	1	Linear	−3.69	1.743
	2	Rhombus	−6.75	1.858
	3	Hexagonal	−7.78	1.819
	4	Slab	8.47	1.936
	5	Chair	−8.57	1.788–1.967
	6	Hexagonal	−9.08	1.891, 1.980
CaO	1	Linear	−5.08	1.818
	2	Rhombus	−8.01	2.005
	3	Ladder	−8.53	1.952–2.294
	4	Slab	−9.63	2.126
	5	Chair	−9.55	1.940–2.204
	6	Slab	−10.06	2.108–2.289
SrO	1	Linear	−5.59	1.928
	2	Rhombus	−8.19	2.140
	3	Ladder	−8.54	2.074–2.389
	4	Slab	−9.38	2.249, 2.256
	5	Ladder	−9.07	2.204–2.341
	6	Slab	−9.90	2.238–2.422
BaO	1	Linear	−6.55	2.031
	2	Rhombus	−8.75	2.277
	3	Ladder	−8.98	2.189–2.512
	4	Slab	−9.97	2.413–2.417
	5	Ladder	−9.31	2.205–2.532
	6	Slab	−10.15	2.374–2.566