Ann: Fully Underwritten Equity Raising - Approximately A$425M, page-4

Not sure how you got $2.01, but the new theoretical share price should be some sort of weighted average between the current share price and the new shares' issue price. One thing you probably forgot to do was to add the value of the cash raised to the new market cap.

Here's a short spread sheet of how to figure out the theoretical new SP (all figures in millions except the SP):

	425	cash raised	A (from ann)
1	185	new shares issued	B (from ann)
2	1867	old MC	C (from HC)
3	2292	total new MC	D (A + C)
4	715	old shares	E (C / 2.61)
5	900	total shares	F (B + E)
6	2.55	theoretical SP	D / F

This is rough and ready. Doesn't include costs of brokerage, which should be subtracted from the new MC, for example, but I couldn't be bothered finding that.
Of course whether it is over or under-subscribed reveals extra information on the depth of demand which will have a significant effect on the final SP and MC.