60        temperature = clamp(temperature, 1e-9, 500.0); 
 
   61        pressure = clamp(pressure, 0.0, 1e8); 
 
   67        constexpr Scalar M_m = 1e3*Mesitylene::molarMass(); 
 
   68        constexpr Scalar M_w = 1e3*H2O::molarMass(); 
 
   69        constexpr Scalar Tb_m = 437.9;        
 
   70        constexpr Scalar Tb_w = 373.15;       
 
   71        constexpr Scalar V_B_w = 18.0;                
 
   74        const Scalar sigma_w = 1.18*cbrt(V_B_w);     
 
   75        constexpr Scalar T_scal_w = 1.15*Tb_w;     
 
   76        constexpr Scalar V_B_m = 162.6;       
 
   77        const Scalar sigma_m = 1.18*cbrt(V_B_m);     
 
   78        const Scalar sigma_wm = 0.5*(sigma_w + sigma_m);
 
   79        constexpr Scalar T_scal_m = 1.15*Tb_m;
 
   80        const Scalar T_scal_wm = sqrt(T_scal_w*T_scal_m);
 
   83        Scalar T_star = temperature/T_scal_wm;
 
   84        T_star = max(T_star, 1e-5); 
 
   86        const Scalar Omega = 1.06036/pow(T_star,0.1561) + 0.193/exp(T_star*0.47635)
 
   87            + 1.03587/exp(T_star*1.52996) + 1.76474/exp(T_star*3.89411);
 
   88        const Scalar B_ = 0.00217 - 0.0005*sqrt(1.0/M_w + 1.0/M_m);
 
   89        const Scalar Mr = (M_w + M_m)/(M_w*M_m);
 
   90        const Scalar D_wm = (B_*pow(temperature, 1.6)*sqrt(Mr))
 
   91                            /(1e-5*pressure*power(sigma_wm, 2)*Omega);