code: def _hugoniot_p(self, v):
          
          rho = self._get_rho(v)
          params = self._set_params(self.params_hugoniot)
          if self.nonlinear:
              return hugoniot_p_nlin(rho, *params)
          else:
              return hugoniot_p(rho, *params)
docs: calculate static pressure at 300 K.
  
          :param v: unit-cell volume in A^3
          :return: static pressure at t_ref (=300 K) in GPa