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!=2) {
  18                 printf("[sic] error: arg1 (vis/log/save location) ");
  19                 printf("must be given!\n");
  20                 return -1;
  21         }
  22
  23         /* main moldyn structure */
  24         t_moldyn md;
  25
  26         /* potential parameters */
  27         t_lj_params lj;
  28         t_ho_params ho;
  29         t_tersoff_mult_params tp;
  30
  31         /* misc parameters */
  32         double tau;
  33
  34         /* testing location & velocity vector */
  35         //t_3dvec r,v;
  36
  37         /* values */
  38         tau=1.0e-15;    /* delta t = 1 fs */
  39
  40         /* initialize moldyn */
  41         printf("[sic] moldyn init\n");
  42         moldyn_init(&md,argc,argv);
  43
  44         /* choose integration algorithm */
  45         printf("[sic] setting integration algorithm\n");
  46         set_int_alg(&md,MOLDYN_INTEGRATE_VERLET);
  47
  48         /* choose potential */
  49         printf("[sic] selecting potential\n");
  50         set_potential1b(&md,tersoff_mult_1bp,&tp);
  51         set_potential2b(&md,tersoff_mult_2bp,&tp);
  52         set_potential2b_post(&md,tersoff_mult_post_2bp,&tp);
  53         set_potential3b(&md,tersoff_mult_3bp,&tp);
  54         //set_potential2b(&md,lennard_jones,&lj);
  55
  56         /*
  57          * potential parameters
  58          */
  59
  60         /* lennard jones */
  61         lj.sigma6=LJ_SIGMA_SI*LJ_SIGMA_SI*LJ_SIGMA_SI;
  62         lj.sigma6*=lj.sigma6;
  63         lj.sigma12=lj.sigma6*lj.sigma6;
  64         lj.epsilon4=4.0*LJ_EPSILON_SI;
  65
  66         /* harmonic oscillator */
  67         ho.equilibrium_distance=0.25*sqrt(3.0)*LC_SI;
  68         ho.spring_constant=1;
  69
  70         /*
  71          * tersoff mult potential parameters for SiC
  72          */
  73         tp.S[0]=TM_S_SI;
  74         tp.R[0]=TM_R_SI;
  75         tp.A[0]=TM_A_SI;
  76         tp.B[0]=TM_B_SI;
  77         tp.lambda[0]=TM_LAMBDA_SI;
  78         tp.mu[0]=TM_MU_SI;
  79         tp.beta[0]=TM_BETA_SI;
  80         tp.n[0]=TM_N_SI;
  81         tp.c[0]=TM_C_SI;
  82         tp.d[0]=TM_D_SI;
  83         tp.h[0]=TM_H_SI;
  84
  85         tp.S[1]=TM_S_C;
  86         tp.R[1]=TM_R_C;
  87         tp.A[1]=TM_A_C;
  88         tp.B[1]=TM_B_C;
  89         tp.lambda[1]=TM_LAMBDA_C;
  90         tp.mu[1]=TM_MU_C;
  91         tp.beta[1]=TM_BETA_C;
  92         tp.n[1]=TM_N_C;
  93         tp.c[1]=TM_C_C;
  94         tp.d[1]=TM_D_C;
  95         tp.h[1]=TM_H_C;
  96
  97         tp.chi=TM_CHI_SIC;
  98
  99         tersoff_mult_complete_params(&tp);
 100
 101         /* cutoff radius */
 102         printf("[sic] setting cutoff radius\n");
 103         set_cutoff(&md,TM_S_SI);
 104         //set_cutoff(&md,2*LC_SI);
 105
 106         /* set (initial) dimensions of simulation volume */
 107         printf("[sic] setting dimensions\n");
 108         set_dim(&md,5*LC_SI,5*LC_SI,5*LC_SI,TRUE);
 109
 110         /* set periodic boundary conditions in all directions */
 111         printf("[sic] setting periodic boundary conditions\n");
 112         set_pbc(&md,TRUE,TRUE,TRUE);
 113
 114         /* create the lattice / place atoms */
 115         printf("[sic] creating atoms\n");
 116         create_lattice(&md,DIAMOND,LC_SI,SI,M_SI,
 117                        ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 118                        0,5,5,5);
 119         moldyn_bc_check(&md);
 120
 121         /* testing configuration */
 122         //r.x=2.45/2;   v.x=0;
 123         //r.y=0;                v.y=0;
 124         //r.z=0;                v.z=0;
 125         //add_atom(&md,SI,M_SI,0,
 126         //           ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 127         //           &r,&v);
 128         //r.x=-2.45/2;  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         //           &r,&v);
 134
 135         /* setting a nearest neighbour distance for the moldyn checks */
 136         set_nn_dist(&md,0.25*sqrt(3.0)*LC_SI); /* diamond ! */
 137
 138         /* set temperature */
 139         printf("[sic] setting temperature\n");
 140         //set_temperature(&md,273.0+1410.0);
 141         set_temperature(&md,273.0+450.0);
 142         //set_temperature(&md,273.0);
 143         //set_temperature(&md,1.0);
 144         //set_temperature(&md,0.0);
 145
 146         /* set pressure */
 147         printf("[sic] setting pressure\n");
 148         set_pressure(&md,ATM);
 149
 150         /* set p/t scaling */
 151         printf("[sic] set p/t scaling\n");
 152         //set_pt_scale(&md,P_SCALE_BERENDSEN,100.0,
 153         //                 T_SCALE_BERENDSEN,100.0);
 154         set_pt_scale(&md,0,0,T_SCALE_BERENDSEN,100.0);
 155
 156         /* initial thermal fluctuations of particles (in equilibrium) */
 157         printf("[sic] thermal init\n");
 158         thermal_init(&md,TRUE);
 159
 160         /* create the simulation schedule */
 161         printf("[sic] adding schedule\n");
 162         moldyn_add_schedule(&md,20001,1.0);
 163
 164         /* activate logging */
 165         printf("[sic] activate logging\n");
 166         moldyn_set_log_dir(&md,argv[1]);
 167         moldyn_set_log(&md,LOG_TOTAL_ENERGY,200);
 168         moldyn_set_log(&md,VISUAL_STEP,200);
 169
 170         /*
 171          * let's do the actual md algorithm now
 172          *
 173          * integration of newtons equations
 174          */
 175
 176         printf("[sic] integration start, go get a coffee ...\n");
 177         moldyn_integrate(&md);
 178
 179         /* close */
 180
 181         printf("[sic] shutdown\n");
 182         moldyn_shutdown(&md);
 183
 184         return 0;
 185 }
 186