def get_elem_wt():
    """Returns dict with built-in element names and atomic weights [kg/kmol].

    Attributes
    ----------
    None

    Returns
    -------
    elem_wt : dict
        Dictionary with element name keys and atomic weight [kg/kmol] values.
    """
    elem_wt = dict([('h', 1.00794), ('he', 4.0026), ('li', 6.939), ('be', 
        9.0122), ('b', 10.811), ('c', 12.011), ('n', 14.00674), ('o', 
        15.9994), ('f', 18.9984), ('ne', 20.183), ('na', 22.9898), ('mg', 
        24.312), ('al', 26.9815), ('si', 28.086), ('p', 30.9738), ('s', 
        32.064), ('cl', 35.453), ('ar', 39.948), ('k', 39.102), ('ca', 
        40.08), ('sc', 44.956), ('ti', 47.9), ('v', 50.942), ('cr', 51.996),
        ('mn', 54.938), ('fe', 55.847), ('co', 58.9332), ('ni', 58.71), (
        'cu', 63.54), ('zn', 65.37), ('ga', 69.72), ('ge', 72.59), ('as', 
        74.9216), ('se', 78.96), ('br', 79.9009), ('kr', 83.8), ('rb', 
        85.47), ('sr', 87.62), ('y', 88.905), ('zr', 91.22), ('nb', 92.906),
        ('mo', 95.94), ('tc', 99.0), ('ru', 101.07), ('rh', 102.905), ('pd',
        106.4), ('ag', 107.87), ('cd', 112.4), ('in', 114.82), ('sn', 
        118.69), ('sb', 121.75), ('te', 127.6), ('i', 126.9044), ('xe', 
        131.3), ('cs', 132.905), ('ba', 137.34), ('la', 138.91), ('ce', 
        140.12), ('pr', 140.907), ('nd', 144.24), ('pm', 145.0), ('sm', 
        150.35), ('eu', 151.96), ('gd', 157.25), ('tb', 158.924), ('dy', 
        162.5), ('ho', 164.93), ('er', 167.26), ('tm', 168.934), ('yb', 
        173.04), ('lu', 174.997), ('hf', 178.49), ('ta', 180.948), ('w', 
        183.85), ('re', 186.2), ('os', 190.2), ('ir', 192.2), ('pt', 195.09
        ), ('au', 196.967), ('hg', 200.59), ('tl', 204.37), ('pb', 207.19),
        ('bi', 208.98), ('po', 210.0), ('at', 210.0), ('rn', 222.0), ('fr',
        223.0), ('ra', 226.0), ('ac', 227.0), ('th', 232.038), ('pa', 231.0
        ), ('u', 238.03), ('np', 237.0), ('pu', 242.0), ('am', 243.0), (
        'cm', 247.0), ('bk', 249.0), ('cf', 251.0), ('es', 254.0), ('fm', 
        253.0), ('d', 2.0141), ('e', 0.000548578)])
    return elem_wt
