(n, a, mass)
return ((n * pi / a)**2) / mass
Returns the Energy psi_{n} for a 1d potential hole with infinity borders

    ``n``
        the "principal" quantum number. Corresponds to the number of nodes in
        the wavefunction.  n >= 0
    ``a``
        width of the well. a > 0
    ``mass``
        mass.
Returns the Energy psi_{n} for a 1d potential hole with infinity borders
Returns the Energy psi_ { n } for a 1d potential hole with infinity borders
def E_n(n, a, mass):
    """
    Returns the Energy psi_{n} for a 1d potential hole with infinity borders

    ``n``
        the "principal" quantum number. Corresponds to the number of nodes in
        the wavefunction.  n >= 0
    ``a``
        width of the well. a > 0
    ``mass``
        mass.
    """
    return ((n * pi / a)**2) / mass
def E_n ( n , a , mass ) : return ( ( n * pi / a ) ** 2 ) / mass