sic.c

   1 /*
   2  * sic.c - investigation of the sic precipitation process of silicon carbide
   3  *
   4  * author: Frank Zirkelbach <frank.zirkelbach@physik.uni-augsburg.de>
   5  *
   6  */
   7
   8 #include <math.h>
   9
  10 #include "moldyn.h"
  11
  12 #include "posic.h"
  13
  14 int main(int argc,char **argv) {
  15
  16         /* check argv */
  17         if(argc!=3) {
  18                 printf("[sic] usage: %s <logdir> <temperatur>\n",argv[0]);
  19                 return -1;
  20         }
  21
  22         /* main moldyn structure */
  23         t_moldyn md;
  24
  25         /* potential parameters */
  26         t_lj_params lj;
  27         t_ho_params ho;
  28         t_tersoff_mult_params tp;
  29
  30         /* misc parameters */
  31         double tau;
  32
  33         /* testing location & velocity vector */
  34         t_3dvec r,v;
  35
  36         /* values */
  37         tau=1.0e-15;    /* delta t = 1 fs */
  38
  39         /* initialize moldyn */
  40         printf("[sic] moldyn init\n");
  41         moldyn_init(&md,argc,argv);
  42
  43         /* choose integration algorithm */
  44         printf("[sic] setting integration algorithm\n");
  45         set_int_alg(&md,MOLDYN_INTEGRATE_VERLET);
  46
  47         /* choose potential */
  48         printf("[sic] selecting potential\n");
  49         //set_potential1b(&md,tersoff_mult_1bp,&tp);
  50         //set_potential2b(&md,tersoff_mult_2bp,&tp);
  51         //set_potential2b_post(&md,tersoff_mult_post_2bp,&tp);
  52         //set_potential3b(&md,tersoff_mult_3bp,&tp);
  53         set_potential2b(&md,lennard_jones,&lj);
  54         //set_potential2b(&md,harmonic_oscillator,&ho);
  55
  56         /* cutoff radius */
  57         printf("[sic] setting cutoff radius\n");
  58         //set_cutoff(&md,TM_S_SI);
  59         set_cutoff(&md,3*LC_SI);
  60
  61         /*
  62          * potential parameters
  63          */
  64
  65         /* lennard jones */
  66         lj.sigma6=LJ_SIGMA_SI*LJ_SIGMA_SI*LJ_SIGMA_SI;
  67         lj.sigma6*=lj.sigma6;
  68         lj.sigma12=lj.sigma6*lj.sigma6;
  69         lj.epsilon4=4.0*LJ_EPSILON_SI;
  70         lj.uc=lj.epsilon4*(lj.sigma12/pow(md.cutoff,12.0)-lj.sigma6/pow(md.cutoff,6));
  71
  72         /* harmonic oscillator */
  73         ho.equilibrium_distance=0.25*sqrt(3.0)*LC_SI;
  74         ho.spring_constant=.1;
  75
  76         /*
  77          * tersoff mult potential parameters for SiC
  78          */
  79         tp.S[0]=TM_S_SI;
  80         tp.R[0]=TM_R_SI;
  81         tp.A[0]=TM_A_SI;
  82         tp.B[0]=TM_B_SI;
  83         tp.lambda[0]=TM_LAMBDA_SI;
  84         tp.mu[0]=TM_MU_SI;
  85         tp.beta[0]=TM_BETA_SI;
  86         tp.n[0]=TM_N_SI;
  87         tp.c[0]=TM_C_SI;
  88         tp.d[0]=TM_D_SI;
  89         tp.h[0]=TM_H_SI;
  90
  91         tp.S[1]=TM_S_C;
  92         tp.R[1]=TM_R_C;
  93         tp.A[1]=TM_A_C;
  94         tp.B[1]=TM_B_C;
  95         tp.lambda[1]=TM_LAMBDA_C;
  96         tp.mu[1]=TM_MU_C;
  97         tp.beta[1]=TM_BETA_C;
  98         tp.n[1]=TM_N_C;
  99         tp.c[1]=TM_C_C;
 100         tp.d[1]=TM_D_C;
 101         tp.h[1]=TM_H_C;
 102
 103         tp.chi=TM_CHI_SIC;
 104
 105         tersoff_mult_complete_params(&tp);
 106
 107         /* set (initial) dimensions of simulation volume */
 108         printf("[sic] setting dimensions\n");
 109         set_dim(&md,10*LC_SI,10*LC_SI,10*LC_SI,TRUE);
 110
 111         /* set periodic boundary conditions in all directions */
 112         printf("[sic] setting periodic boundary conditions\n");
 113         set_pbc(&md,TRUE,TRUE,TRUE);
 114
 115         /* create the lattice / place atoms */
 116         printf("[sic] creating atoms\n");
 117         create_lattice(&md,DIAMOND,LC_SI,SI,M_SI,
 118         //               ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 119                        ATOM_ATTR_2BP|ATOM_ATTR_HB,
 120                        0,10,10,10);
 121         moldyn_bc_check(&md);
 122
 123         /* testing configuration */
 124         //r.x=0.28*sqrt(3)*LC_SI/2;     v.x=0;
 125         //r.x=1.75*LC_SI;       v.x=-0.01;
 126         //r.y=0;                v.y=0;
 127         //r.z=0;                v.z=0;
 128         //add_atom(&md,SI,M_SI,0,
 129         //           ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 130         //           ATOM_ATTR_2BP|ATOM_ATTR_HB,
 131         //           &r,&v);
 132         //r.x=-r.x;     v.x=-v.x;
 133         //r.y=0;                v.y=0;
 134         //r.z=0;                v.z=0;
 135         //add_atom(&md,SI,M_SI,0,
 136         //           ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 137         //           ATOM_ATTR_2BP|ATOM_ATTR_HB,
 138         //           &r,&v);
 139
 140         /* setting a nearest neighbour distance for the moldyn checks */
 141         set_nn_dist(&md,0.25*sqrt(3.0)*LC_SI); /* diamond ! */
 142
 143         /* set temperature */
 144         printf("[sic] setting temperature -> %f\n",273+atof(argv[2]));
 145         //set_temperature(&md,273.0+1410.0);
 146         //set_temperature(&md,273.0+450.0);
 147         //set_temperature(&md,273.0);
 148         //set_temperature(&md,1.0);
 149         //set_temperature(&md,0.0);
 150         set_temperature(&md,atof(argv[2])+273.0);
 151
 152         /* set pressure */
 153         printf("[sic] setting pressure\n");
 154         set_pressure(&md,ATM);
 155
 156         /* set p/t scaling */
 157         printf("[sic] set p/t scaling\n");
 158         //set_pt_scale(&md,P_SCALE_BERENDSEN,100.0,
 159         //                 T_SCALE_BERENDSEN,100.0);
 160         //set_pt_scale(&md,0,0,T_SCALE_BERENDSEN,100.0);
 161         //set_pt_scale(&md,P_SCALE_BERENDSEN,100.0,0,0);
 162
 163         /* initial thermal fluctuations of particles (in equilibrium) */
 164         printf("[sic] thermal init\n");
 165         thermal_init(&md,TRUE);
 166
 167         /* create the simulation schedule */
 168         printf("[sic] adding schedule\n");
 169         moldyn_add_schedule(&md,10001,1.0);
 170
 171         /* activate logging */
 172         printf("[sic] activate logging\n");
 173         moldyn_set_log_dir(&md,argv[1]);
 174         moldyn_set_log(&md,LOG_TOTAL_ENERGY,10);
 175         moldyn_set_log(&md,VISUAL_STEP,100);
 176
 177         /*
 178          * let's do the actual md algorithm now
 179          *
 180          * integration of newtons equations
 181          */
 182
 183         printf("[sic] integration start, go get a coffee ...\n");
 184         moldyn_integrate(&md);
 185
 186         /* close */
 187
 188         printf("[sic] shutdown\n");
 189         moldyn_shutdown(&md);
 190
 191         return 0;
 192 }
 193