    int n_step = 10000000; // Number of time steps //used  10000000
    dt = 0.00001; // Time step size used 0.001
    Npart=100

    zuerst für f=0
    Dann für alle anderen

    int n_part = 1000; 

        int n_step = 1000000; // Number of time steps //used  10000000
    dt = 0.0001; // Time step size used 0.001