code: public static float[] getUnitCellAsArray(PDBCrystallographicInfo xtalInfo) {
  		CrystalCell xtalCell = xtalInfo.getCrystalCell();
  		if(xtalCell==null){
  			return null;
  		}else{
  			float[] inputUnitCell = new float[6];
  			inputUnitCell[0] = (float) xtalCell.getA();
  			inputUnitCell[1] = (float) xtalCell.getB();
  			inputUnitCell[2] = (float) xtalCell.getC();
  			inputUnitCell[3] = (float) xtalCell.getAlpha();
  			inputUnitCell[4] = (float) xtalCell.getBeta();
  			inputUnitCell[5] = (float) xtalCell.getGamma();
  			return inputUnitCell;
  		}
  	}
docs: Get the length six array of the unit cell information.
  @param xtalInfo the input PDBCrystallographicInfo object
  @return the length six float array