import pulsar as psr
def load_ref_system():
    """ Returns norbornane as found in the IQMol fragment library.
        All credit to https://github.com/nutjunkie/IQmol
    """
    return psr.make_system("""
        C      0.9665      1.0824      0.5413
        C      1.2773     -0.4115      0.7732
        C      0.2828     -1.1346     -0.1576
        C     -1.1303     -0.9646      0.4366
        C     -1.4411      0.5293      0.2046
        C     -0.1729      1.0557     -0.4978
        C      0.2273     -0.1635     -1.3572
        H      1.8453      1.6266      0.1530
        H      0.6690      1.6004      1.4697
        H      1.1499     -0.7100      1.8284
        H      2.3205     -0.6573      0.5074
        H      0.5550     -2.1799     -0.3874
        H     -1.1674     -1.2423      1.5044
        H     -1.8581     -1.6172     -0.0769
        H     -1.6481      1.0681      1.1457
        H     -2.3332      0.6664     -0.4315
        H     -0.3162      2.0081     -1.0381
        H      1.1910     -0.0439     -1.8783
        H     -0.5219     -0.4374     -2.1175
        """)
