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
  55         /*
  56          * potential parameters
  57          */
  58
  59         /* lennard jones */
  60         lj.sigma6=LJ_SIGMA_SI*LJ_SIGMA_SI*LJ_SIGMA_SI;
  61         lj.sigma6*=lj.sigma6;
  62         lj.sigma12=lj.sigma6*lj.sigma6;
  63         lj.epsilon4=4.0*LJ_EPSILON_SI;
  64
  65         /* harmonic oscillator */
  66         ho.equilibrium_distance=0.25*sqrt(3.0)*LC_SI;
  67         ho.spring_constant=1;
  68
  69         /*
  70          * tersoff mult potential parameters for SiC
  71          */
  72         tp.S[0]=TM_S_SI;
  73         tp.R[0]=TM_R_SI;
  74         tp.A[0]=TM_A_SI;
  75         tp.B[0]=TM_B_SI;
  76         tp.lambda[0]=TM_LAMBDA_SI;
  77         tp.mu[0]=TM_MU_SI;
  78         tp.beta[0]=TM_BETA_SI;
  79         tp.n[0]=TM_N_SI;
  80         tp.c[0]=TM_C_SI;
  81         tp.d[0]=TM_D_SI;
  82         tp.h[0]=TM_H_SI;
  83
  84         tp.S[1]=TM_S_C;
  85         tp.R[1]=TM_R_C;
  86         tp.A[1]=TM_A_C;
  87         tp.B[1]=TM_B_C;
  88         tp.lambda[1]=TM_LAMBDA_C;
  89         tp.mu[1]=TM_MU_C;
  90         tp.beta[1]=TM_BETA_C;
  91         tp.n[1]=TM_N_C;
  92         tp.c[1]=TM_C_C;
  93         tp.d[1]=TM_D_C;
  94         tp.h[1]=TM_H_C;
  95
  96         tp.chi=TM_CHI_SIC;
  97
  98         tersoff_mult_complete_params(&tp);
  99
 100         /* cutoff radius */
 101         printf("[sic] setting cutoff radius\n");
 102         set_cutoff(&md,TM_S_SI);
 103         //set_cutoff(&md,2*LC_SI);
 104
 105         /* set (initial) dimensions of simulation volume */
 106         printf("[sic] setting dimensions\n");
 107         set_dim(&md,5*LC_SI,5*LC_SI,5*LC_SI,TRUE);
 108
 109         /* set periodic boundary conditions in all directions */
 110         printf("[sic] setting periodic boundary conditions\n");
 111         set_pbc(&md,TRUE,TRUE,TRUE);
 112
 113         /* create the lattice / place atoms */
 114         printf("[sic] creating atoms\n");
 115         //create_lattice(&md,DIAMOND,LC_SI,SI,M_SI,
 116         //               ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 117         //               0,5,5,5);
 118         //moldyn_bc_check(&md);
 119
 120         /* testing configuration */
 121         r.x=2.8/2;      v.x=0;
 122         r.y=0;          v.y=0;
 123         r.z=0;          v.z=0;
 124         add_atom(&md,SI,M_SI,0,
 125                    ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP,//|ATOM_ATTR_HB,
 126         //           ATOM_ATTR_2BP,
 127                    &r,&v);
 128         r.x=-2.8/2;     v.x=0;
 129         r.y=0;          v.y=0;
 130         r.z=0;          v.z=0;
 131         add_atom(&md,SI,M_SI,0,
 132                    ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP,//|ATOM_ATTR_HB,
 133         //           ATOM_ATTR_2BP,
 134                    &r,&v);
 135
 136         /* setting a nearest neighbour distance for the moldyn checks */
 137         set_nn_dist(&md,0.25*sqrt(3.0)*LC_SI); /* diamond ! */
 138
 139         /* set temperature */
 140         printf("[sic] setting temperature -> %f\n",273+atof(argv[2]));
 141         //set_temperature(&md,273.0+1410.0);
 142         //set_temperature(&md,273.0+450.0);
 143         //set_temperature(&md,273.0);
 144         //set_temperature(&md,1.0);
 145         //set_temperature(&md,0.0);
 146         set_temperature(&md,atof(argv[2])+273.0);
 147
 148         /* set pressure */
 149         printf("[sic] setting pressure\n");
 150         set_pressure(&md,ATM);
 151
 152         /* set p/t scaling */
 153         printf("[sic] set p/t scaling\n");
 154         //set_pt_scale(&md,P_SCALE_BERENDSEN,100.0,
 155         //                 T_SCALE_BERENDSEN,100.0);
 156         //set_pt_scale(&md,0,0,T_SCALE_BERENDSEN,100.0);
 157
 158         /* initial thermal fluctuations of particles (in equilibrium) */
 159         printf("[sic] thermal init\n");
 160         //thermal_init(&md,TRUE);
 161
 162         /* create the simulation schedule */
 163         printf("[sic] adding schedule\n");
 164         moldyn_add_schedule(&md,10000,.1);
 165
 166         /* activate logging */
 167         printf("[sic] activate logging\n");
 168         moldyn_set_log_dir(&md,argv[1]);
 169         moldyn_set_log(&md,LOG_TOTAL_ENERGY,1);
 170         moldyn_set_log(&md,VISUAL_STEP,20);
 171
 172         /*
 173          * let's do the actual md algorithm now
 174          *
 175          * integration of newtons equations
 176          */
 177
 178         printf("[sic] integration start, go get a coffee ...\n");
 179         moldyn_integrate(&md);
 180
 181         /* close */
 182
 183         printf("[sic] shutdown\n");
 184         moldyn_shutdown(&md);
 185
 186         return 0;
 187 }
 188