Ab Initio Studies on Hematite Surface and the Adsorption of Phosphate

Table 1

Derived crystal parameters of various forms of hematite.

Parameters	Crystal systems	Derived in this work	Experimental value
Cell dimensions (Å)	(i) NM	= = 4.7405, = 13.6279	= = 5.035^2,; = 13.72^2
	(ii) SP	= = 4.8058, = 13.2919
	(iii) AFM	= = 4.9658, = 13.9104
Bulk modulus (Gpa)	(i) NM	274.8133	230^3
	(ii) SP	255.9203
	(iii) AFM	184.5472
Coefficient of bulk modulus	(i) NM	4.8655	3.5^3
	(ii) SP	13.5683
	(iii) AFM	5.8852
Cohesive energy (eV/formula unit)	(i) NM	−27.8402	−25.171^3
	(ii) SP	−28.1210
	(iii) AFM	−33.4725

NM: nonmagnetic, SP: spin polarized, and AFM: antiferromagnetic.