import CoolProp
CPmod = CoolProp.CoolProp

def get_offset_NBP(name):
    #CPmod.set_debug_level(10)
    CPmod.set_reference_state(name,"RESET")
    HEOS = CoolProp.AbstractState('HEOS', name)
    HEOS.update(CoolProp.PQ_INPUTS, 101325, 0)

    gas_constant = HEOS.gas_constant()/HEOS.molar_mass()

    delta_a1 = HEOS.smass()/(gas_constant)
    delta_a2 = -HEOS.hmass()/(gas_constant*HEOS.keyed_output(CoolProp.iT_reducing))
    return delta_a1, delta_a2
    
if __name__=='__main__':
    name = 'MM'
    print get_offset_NBP(name)