void calculate() throws ScriptException {
		if (statementLength == 1)
			evalError(GT._("Calculate what?") + "hbonds?  surface? structure?");
		switch (statement[1].tok) {
		case Token.surface:
			dots(2, Dots.DOTS_MODE_CALCONLY);
			viewer.addStateScript("calculate surface");
			return;
		case Token.hbond:
			viewer.autoHbond();
			return;
		case Token.structure:
			viewer.calculateStructures();
			return;
		}
	}