import pulsar as psr
def load_ref_system():
    """ Returns l-tryptophan as found in the IQMol fragment library.
        All credit to https://github.com/nutjunkie/IQmol
    """
    return psr.make_system("""
        N     -1.3289      1.0488     -1.5596
        C      0.1286      1.0198     -1.8261
        C      0.3335      0.8585     -3.3268
        O     -0.0551     -0.0282     -4.0649
        O      1.0668      1.8338     -3.9108
        C      0.8906     -0.1043     -1.0999
        H      1.9534     -0.0888     -1.4126
        H      0.4975     -1.0987     -1.3971
        C      0.8078      0.0465      0.3677
        C      1.5802      0.8809      1.1516
        N      1.1567      0.7746      2.4944
        H      1.7094      1.0499      3.2650
        C      0.1694     -0.2350      2.5662
        C     -0.0897     -0.6721      1.2403
        C     -1.0740     -1.6418      1.0106
        H     -1.2812     -1.9849     -0.0088
        C     -1.7623     -2.1470      2.0948
        H     -2.5346     -2.9080      1.9416
        C     -1.4948     -1.7069      3.4060
        H     -2.0660     -2.1385      4.2348
        C     -0.5337     -0.7507      3.6638
        H     -0.3249     -0.4086      4.6819
        H      2.3719      1.5631      0.8380
        H     -1.4726      1.2086     -0.5841
        H     -1.7404      0.1740     -1.8129
        H      0.5299      2.0096     -1.4901
        H      1.1361      1.6737     -4.8470
        """)
