calculate Debye temperature for Altshuler equation

    :param v: unit-cell volume in A^3
    :param v0: unit-cell volume in A^3 at 1 bar
    :param gamma0: Gruneisen parameter at 1 bar
    :param gamma_inf: Gruneisen parameter at infinite pressure
    :param beta: volume dependence of Gruneisen parameter
    :param theta0: Debye temperature at 1 bar in K
    :return: Debye temperature in K

def altshuler_debyetemp(v, v0, gamma0, gamma_inf, beta, theta0):
    """
    calculate Debye temperature for Altshuler equation

    :param v: unit-cell volume in A^3
    :param v0: unit-cell volume in A^3 at 1 bar
    :param gamma0: Gruneisen parameter at 1 bar
    :param gamma_inf: Gruneisen parameter at infinite pressure
    :param beta: volume dependence of Gruneisen parameter
    :param theta0: Debye temperature at 1 bar in K
    :return: Debye temperature in K
    """
    x = v / v0
    if isuncertainties([v, v0, gamma0, gamma_inf, beta, theta0]):
        theta = theta0 * np.power(x, -1. * gamma_inf) *\
            unp.exp((gamma0 - gamma_inf) / beta * (1. - np.power(x, beta)))
    else:
        theta = theta0 * np.power(x, -1. * gamma_inf) *\
            np.exp((gamma0 - gamma_inf) / beta * (1. - np.power(x, beta)))
    return theta