code: def tsuchiya_pel(v, temp, v0, a, b, c, d, n, z, three_r=3. * constants.R,
                   t_ref=300.):
      
      def f(temp):
          return a + b * temp + c * np.power(temp, 2.) + d * np.power(temp, 3.)
      return f(temp) - f(t_ref)
docs: calculate electronic contributions in pressure for the Tsuchiya equation
  
      :param v: unit-cell volume in A^3
      :param temp: temperature in K
      :param v0: unit-cell volume in A^3 at 1 bar
      :param a: parameter for the Tsuchiya equation
      :param b: parameter for the Tsuchiya equation
      :param c: parameter for the Tsuchiya equation
      :param d: parameter for the Tsuchiya equation
      :param n: number of atoms in a formula unit
      :param z: number of formula unit in a unit cell
      :param t_ref: reference temperature, 300 K
      :param three_r: 3 times gas constant
      :return: electronic contribution in GPa
      :note: n, z, three_r are not used but in there for consistency
          with other electronic contribution equations