def Lastovka_solid_integral(T, similarity_variable):
A1 = <NUM_LIT><EOL>A2 = <NUM_LIT><EOL>theta = <NUM_LIT><EOL>C1 = <NUM_LIT><EOL>C2 = -<NUM_LIT><EOL>D1 = <NUM_LIT><EOL>D2 = -<NUM_LIT><EOL>similarity_variable2 = similarity_variable*similarity_variable<EOL>return (T*T*T*(<NUM_LIT>*D1*similarity_variable/<NUM_LIT> <EOL>+ <NUM_LIT>*D2*similarity_variable2/<NUM_LIT>) + T*T*(<NUM_LIT>*C1*similarity_variable <EOL>+ <NUM_LIT>*C2*similarity_variable2)<EOL>+ (<NUM_LIT>*A1*R*similarity_variable*theta<EOL>+ <NUM_LIT>*A2*R*similarity_variable2*theta)/(exp(theta/T) - <NUM_LIT:1.>))<EOL>
r'''Integrates solid constant-pressure heat capacitiy with the similarity
    variable concept and method as shown in [1]_.

    Uses a explicit form as derived with Sympy.

    Parameters
    ----------
    T : float
        Temperature of solid [K]
    similarity_variable : float
        similarity variable as defined in [1]_, [mol/g]

    Returns
    -------
    H : float
        Difference in enthalpy from 0 K, [J/kg]

    Notes
    -----
    Original model is in terms of J/g/K. Note that the model is for predicting
    mass heat capacity, not molar heat capacity like most other methods!

    See Also
    --------
    Lastovka_solid

    Examples
    --------
    >>> Lastovka_solid_integral(300, 0.2139)
    283246.1242170376

    References
    ----------
    .. [1] Laštovka, Václav, Michal Fulem, Mildred Becerra, and John M. Shaw.
       "A Similarity Variable for Estimating the Heat Capacity of Solid Organic
       Compounds: Part II. Application: Heat Capacity Calculation for
       Ill-Defined Organic Solids." Fluid Phase Equilibria 268, no. 1-2
       (June 25, 2008): 134-41. doi:10.1016/j.fluid.2008.03.018.