Text this: Crystal structure of bis{[4,4,5,5-tetramethyl-2-(1-methyl-1H-benzimidazol- 2-yl)-4,5-dihydroimidazole-1-oxyl-3-oxide-κ2 N,O]- (μ2-thiocyanato-N:S)(thiocyanato-κS)mercury(II)}, Hg2(C15H19N4O2)2(SCN)4