" it has not been clear what role these play " It Has Not Been Clear

'phosphorous' - should be 'phosphorus'

Computer simulations can be completely different then real world practises. A metalic glass can change everything from cooking appliances to space travel. Time to try real world development.

From clarity to clarity - liquid to glass. (Spinning of Walter Mrak.)

'phosphorous' - should be 'phosphorus'

Unless it's British English you're writing, when 'phosphorous' is correct.