Use of a metallocene compound of general formula Ind2R″MQ2 as a component of a catalyst system in producing polyethylene, wherein each Ind is the same or different and is indenyl or substituted indenyl; R″ is a bridge which comprises a C1 to C4 alkylene radical, a dialkyl germanium or silicon or siloxane, alkyl phosphine or amine, which bridge is substituted or unsubstituted, M is a Group IV metal or vanadium and each Q is hydrocarbyl having 1 to 20 carbon atoms or halogen; and the ratio of meso to racemic forms of the metallocene in the catalyst system is at least 1:3. The metallocene may be supported. The ethylene may be polymerized in a reaction medium that is substantially free of any external comonomer, with comonomer being formed in situ. The produced polyethylene may have long chain branching. The produced polyethylene may be atactic.