// Nitrogen

#include "Nitrogen.h"
#include <math.h>
#include <iostream>
using namespace std;

namespace tpx {


    static const double M  = 28.01348,
                       Tmn = 63.15,
                       Tmx = 2000.0,
                        Tc = 126.200,
                        Pc = 3.4e6,
                       Roc = 314.03,
                        To = 63.15,
                         R = 2.96790515164171e2,
                     Gamma = 7.13602531283233e-6,
                     alpha = 1.95,
                      beta = 3353.40610,
                        u0 = 150877.551,
                        s0 = 214.9352518;


    static const double Ann[] = {  
        1.75889959256970e-1,  1.38197604384933e1,  -3.14918412133921e2,
        4.40300150239380e3,  -5.45358971644916e5, 4.84413320182919e-4,
        -5.18964416491365e-2,  6.57265859197103e-4 ,8.51299771713314e4 ,
        1.33459405162578e-8,  3.83381319826746e-4, -8.35421151028455e-2,
        2.84874912286101e-7,
        -2.38296116270360e-7, -1.48321912935764e-4, 5.62605853190540e-10,
        -2.98201050924595e-13, 9.85319087685241e-11, -1.92002176056468e-14,
        -7.82250103373122e4,  -5.51801778744598e5, -5.72781957607352e-1,
        3.25760529488327e2,  -1.34659309828737e-6, -1.92036423064911e-5,
        -3.94564337674524e-12,-2.44388245328965e-9, -1.50970602460077e-18,
        1.25854885346038e-16,-8.34271144923969e-24, -1.17299202018417e-22, 
        9.06544823455730e-22
    };

    static const double Fnn[]=
    {  8.3944094440e3, -1.8785191705e3, -7.2822291650, 
       1.0228509660e-2, 5.5560638250e-4,
      -5.9445446620e-6, 2.7154339320e-8, 
       -4.8795359040e-11, 5.0953608240e2  };

    static const double Dnn[] =
    {  3.1402991e2, 4.4111015e2, 9.4622994e2 ,
       -2.9067111e3, 4.4785979e3, -2.2746914e3  };

    static const double Gnn[] =
    {  -2.18203473713518e5, 1.01573580096247e4, -1.65504721657240e2,
       7.43175999190430e2, -5.14605623546025e-3,
       5.18347156760489e-6, -1.05922170493616e-9, 2.98389393363817e2  };


    //equation P4
    double nitrogen::C(int i, double rt, double rt2) {
        switch(i) {
        case 0 : 
            return Ann[0] * T + Ann[1] * sqrt(T) 
                + Ann[2] + (Ann[3] + Ann[4] * rt) * rt;
        case 1 : 
            return Ann[5] * T + Ann[6] + rt * (Ann[7] + Ann[8] * rt);
        case 2 :
            return Ann[9] * T + Ann[10] + Ann[11] * rt; 
        case 3 :
            return Ann[12];
        case 4 :
            return rt*(Ann[13] + Ann[14]*rt);
        case 5 :
            return Ann[15]*rt;
        case 6 : 
            return rt*(Ann[16] + Ann[17]*rt);
        case 7 : 
            return Ann[18]*rt2;
        case 8 : 
            return rt2*(Ann[19] + Ann[20]*rt);
        case 9 : 
            return rt2*(Ann[21] + Ann[22]*rt2);
        case 10 : 
            return rt2*(Ann[23] + Ann[24]*rt);
        case 11 : 
            return rt2*(Ann[25] + Ann[26]*rt2);
        case 12 : 
            return rt2*(Ann[27] + Ann[28]*rt);
        case 13 : 
            return rt2*(Ann[29] + Ann[30]*rt + Ann[31]*rt2);
        default :
            return 0.0;
        }
    }

    double nitrogen::Cprime(int i, double rt, double rt2, double rt3) {
        switch(i) {
        case 0 : 
            return Ann[0] + 0.5*Ann[1]/sqrt(T) - (Ann[3] + 2.0*Ann[4]*rt)*rt2; 
        case 1 : 
            return Ann[5] - rt2*(Ann[7] + 2.0*Ann[8]*rt); 
        case 2 :
            return Ann[9] - Ann[11]*rt2; 
        case 3 :
            return 0.0;
        case 4 :
            return -rt2*(Ann[13] + 2.0*Ann[14]*rt);
        case 5 :
            return -Ann[15]*rt2;
        case 6 : 
            return -rt2*(Ann[16] + 2.0*Ann[17]*rt);
        case 7 : 
            return -2.0*Ann[18]*rt3; 
        case 8 : 
            return -rt3*(2.0*Ann[19] + 3.0*Ann[20]*rt);
        case 9 : 
            return -rt3*(2.0*Ann[21] + 4.0*Ann[22]*rt2);
        case 10 : 
            return -rt3*(2.0*Ann[23] + 3.0*Ann[24]*rt);
        case 11 : 
            return -rt3*(2.0*Ann[25] + 4.0*Ann[26]*rt2);
        case 12 : 
            return -rt3*(2.0*Ann[27] + 3.0*Ann[28]*rt);
        case 13 : 
            return -rt3*(2.0*Ann[29] + 3.0*Ann[30]*rt + 4.0*Ann[31]*rt2);
        default :
            return 0.0;
        }
    } 

    double nitrogen::W(int n, double egrho) {
        return (n == 0 ? (1.0 - egrho)/(2.0*Gamma) : 
            (n*W(n-1, egrho) - 0.5*pow(Rho,2*n)*egrho)/Gamma);
    }

    double nitrogen::H(int i, double egrho) {
        return (i < 8 ? pow(Rho,i+2) : pow(Rho,2*i-13)*egrho); 
    }

    double nitrogen::I(int i, double egrho) {
        return (i < 8 ? pow(Rho,i+1)/double(i+1) : W(i-8, egrho)); 
    }

    double nitrogen::up(){
        double rt = 1.0/T;
        double rt2 = rt*rt;
        double rt3 = rt*rt2;
        double egrho = exp(-Gamma*Rho*Rho);
        
        double sum = 0.0;
        for (int i=0; i<14; i++)
            sum += (C(i,rt,rt2) - T*Cprime(i,rt,rt2,rt3))*I(i,egrho);
        
        sum += (((0.25*Gnn[6]*T + Gnn[5]/3.0)*T 
                    + 0.5*Gnn[4])*T + Gnn[3])*T + Gnn[2]*log(T)
               - (Gnn[1] + 0.5*Gnn[0]*rt)*rt 
               + Gnn[7]*beta/(exp(beta*rt) - 1.0) + u0
               + m_energy_offset;
        
        return sum;
    }


    double nitrogen::sp() {
        double rt = 1.0/T;
        double rt2 = rt*rt;
        double rt3 = rt*rt2;
        double egrho = exp(-Gamma*Rho*Rho);

        double sum = 0.0;
        sum = s0 + m_entropy_offset - R*log(Rho);
        for (int i=0; i<14; i++)
            sum -= Cprime(i,rt,rt2,rt3)*I(i,egrho);
        
        sum += (((Gnn[6]/3.0)*T + 0.5*Gnn[5])*T + Gnn[4])*T + Gnn[3]*log(T)
               -((Gnn[0]*rt/3.0 + 0.5*Gnn[1])*rt + Gnn[2])*rt 
               + Gnn[7]*(beta*rt + beta*rt/(exp(beta*rt) - 1.0)
                   - log(exp(beta*rt) - 1.0));
        return sum;
    }
    
    double nitrogen::Pp(){
        double rt = 1.0/T;
        double rt2 = rt*rt;
        double egrho = exp(-Gamma*Rho*Rho);
        
        double P = Rho*R*T;
        for(int i=0; i<14; i++)
            P += C(i,rt,rt2)*H(i,egrho);
        return P;
    }

    //equation s4
    double nitrogen::Psat(){
        double lnp;
        int i;
        if ((T < Tmn) || (T > Tc)) set_Err(TempError);
        for (i=0, lnp=0; i<=7;i++){
            if (i==3) lnp+=Fnn[i]*pow(Tc-T, alpha);
            else lnp+=Fnn[i]*pow(T,i-1);
        }
        lnp+=Fnn[8]*log(T);
        return exp(lnp);
    }
    
    //equation D2
    double nitrogen::ldens(){
        double xx=1-T/Tc, sum=0;
        if ((T < Tmn) || (T > Tc)) set_Err(TempError);
        for(int i=0;i<=5;i++)
            sum+=Dnn[i]*pow(xx,double(i)/3.0);
        return sum;
    }
    
    double nitrogen::Tcrit() {return Tc;}
    double nitrogen::Pcrit() {return Pc;}
    double nitrogen::Vcrit() {return 1.0/Roc;}
    double nitrogen::Tmin() {return Tmn;}
    double nitrogen::Tmax() {return Tmx;}
    char * nitrogen::name() {return (char *) m_name.c_str();}
    char * nitrogen::formula() {return (char *) m_formula.c_str();}
    double nitrogen::MolWt() {return M;}    
}