def parse_output(output_file):
    """Parse output file for void fraction data.

    Args:
        output_file (str): path to simulation output file.

    Returns:
        results (dict): total unit cell, gravimetric, and volumetric surface
            areas.

    """
    results = {}
    with open(output_file) as origin:
        count = 0
        for line in origin:
            if "Surface area" in line:
                if count == 0:
                    results['sa_unit_cell_surface_area'] = float(line.split()[2])
                    count = count + 1
                elif count == 1:
                    results['sa_gravimetric_surface_area'] = float(line.split()[2])
                    count = count + 1
                elif count == 2:
                    results['sa_volumetric_surface_area'] = float(line.split()[2])

    print(
        "\nSURFACE AREA\n" +
        "%s\tA^2\n"      % (results['sa_unit_cell_surface_area']) +
        "%s\tm^2/g\n"    % (results['sa_gravimetric_surface_area']) +
        "%s\tm^2/cm^3"   % (results['sa_volumetric_surface_area']))
    return results