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         /* main moldyn structure */
  16         t_moldyn md;
  17
  18         /* potential parameters */
  19         t_lj_params lj;
  20         t_ho_params ho;
  21         t_tersoff_mult_params tp;
  22
  23         /* misc parameters */
  24         double tau;
  25
  26         /* testing location & velocity vector */
  27         t_3dvec r,v;
  28
  29         /* values */
  30         tau=1.0e-15;    /* delta t = 1 fs */
  31
  32         /* initialize moldyn */
  33         printf("[sic] moldyn init\n");
  34         moldyn_init(&md,argc,argv);
  35
  36         /* choose integration algorithm */
  37         printf("[sic] setting integration algorithm\n");
  38         set_int_alg(&md,MOLDYN_INTEGRATE_VERLET);
  39
  40         /* choose potential */
  41         printf("[sic] selecting potential\n");
  42         set_potential1b(&md,tersoff_mult_1bp,&tp);
  43         set_potential2b(&md,tersoff_mult_2bp,&tp);
  44         set_potential2b_post(&md,tersoff_mult_post_2bp,&tp);
  45         set_potential3b(&md,tersoff_mult_3bp,&tp);
  46         //set_potential2b(&md,lennard_jones,&lj);
  47
  48         /*
  49          * potential parameters
  50          */
  51
  52         /* lennard jones */
  53         lj.sigma6=LJ_SIGMA_SI*LJ_SIGMA_SI*LJ_SIGMA_SI;
  54         lj.sigma6*=lj.sigma6;
  55         lj.sigma12=lj.sigma6*lj.sigma6;
  56         lj.epsilon4=4.0*LJ_EPSILON_SI;
  57
  58         /* harmonic oscillator */
  59         ho.equilibrium_distance=0.25*sqrt(3.0)*LC_SI;
  60         ho.spring_constant=1;
  61
  62         /*
  63          * tersoff mult potential parameters for SiC
  64          */
  65         tp.S[0]=TM_S_SI;
  66         tp.R[0]=TM_R_SI;
  67         tp.A[0]=TM_A_SI;
  68         tp.B[0]=TM_B_SI;
  69         tp.lambda[0]=TM_LAMBDA_SI;
  70         tp.mu[0]=TM_MU_SI;
  71         tp.beta[0]=TM_BETA_SI;
  72         tp.n[0]=TM_N_SI;
  73         tp.c[0]=TM_C_SI;
  74         tp.d[0]=TM_D_SI;
  75         tp.h[0]=TM_H_SI;
  76
  77         tp.S[1]=TM_S_C;
  78         tp.R[1]=TM_R_C;
  79         tp.A[1]=TM_A_C;
  80         tp.B[1]=TM_B_C;
  81         tp.lambda[1]=TM_LAMBDA_C;
  82         tp.mu[1]=TM_MU_C;
  83         tp.beta[1]=TM_BETA_C;
  84         tp.n[1]=TM_N_C;
  85         tp.c[1]=TM_C_C;
  86         tp.d[1]=TM_D_C;
  87         tp.h[1]=TM_H_C;
  88
  89         tp.chi=TM_CHI_SIC;
  90
  91         tersoff_mult_complete_params(&tp);
  92
  93         /* cutoff radius */
  94         printf("[sic] setting cutoff radius\n");
  95         set_cutoff(&md,TM_S_SI);
  96         //set_cutoff(&md,2*LC_SI);
  97
  98         /* set (initial) dimensions of simulation volume */
  99         printf("[sic] setting dimensions\n");
 100         set_dim(&md,5*LC_SI,5*LC_SI,5*LC_SI,TRUE);
 101
 102         /* set periodic boundary conditions in all directions */
 103         printf("[sic] setting periodic boundary conditions\n");
 104         set_pbc(&md,TRUE,TRUE,TRUE);
 105
 106         /* create the lattice / place atoms */
 107         printf("[sic] creating atoms\n");
 108         create_lattice(&md,DIAMOND,LC_SI,SI,M_SI,
 109                        ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 110                        0,5,5,5);
 111         moldyn_bc_check(&md);
 112
 113         /* testing configuration */
 114         //r.x=2.45/2;   v.x=0;
 115         //r.y=0;                v.y=0;
 116         //r.z=0;                v.z=0;
 117         //add_atom(&md,SI,M_SI,0,
 118         //           ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 119         //           &r,&v);
 120         //r.x=-2.45/2;  v.x=0;
 121         //r.y=0;                v.y=0;
 122         //r.z=0;                v.z=0;
 123         //add_atom(&md,SI,M_SI,0,
 124         //           ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 125         //           &r,&v);
 126
 127         /* setting a nearest neighbour distance for the moldyn checks */
 128         set_nn_dist(&md,0.25*sqrt(3.0)*LC_SI); /* diamond ! */
 129
 130         /* set temperature */
 131         printf("[sic] setting temperature\n");
 132         set_temperature(&md,273.0+1410.0);
 133         //set_temperature(&md,273.0+450.0);
 134         //set_temperature(&md,273.0);
 135         //set_temperature(&md,1.0);
 136         //set_temperature(&md,0.0);
 137
 138         /* set pressure */
 139         printf("[sic] setting pressure\n");
 140         set_pressure(&md,ATM);
 141
 142         /* set p/t scaling */
 143         printf("[sic] set p/t scaling\n");
 144         //set_pt_scale(&md,P_SCALE_BERENDSEN,100.0,
 145         //                 T_SCALE_BERENDSEN,100.0);
 146
 147         /* initial thermal fluctuations of particles (in equilibrium) */
 148         printf("[sic] thermal init\n");
 149         thermal_init(&md,TRUE);
 150
 151         /* create the simulation schedule */
 152         printf("[sic] adding schedule\n");
 153         moldyn_add_schedule(&md,100001,1.0);
 154
 155         /* activate logging */
 156         printf("[sic] activate logging\n");
 157         moldyn_set_log_dir(&md,"saves/si_melting_point");
 158         moldyn_set_log(&md,LOG_TOTAL_ENERGY,200);
 159         moldyn_set_log(&md,VISUAL_STEP,200);
 160
 161         /*
 162          * let's do the actual md algorithm now
 163          *
 164          * integration of newtons equations
 165          */
 166
 167         printf("[sic] integration start, go get a coffee ...\n");
 168         moldyn_integrate(&md);
 169
 170         /* close */
 171
 172         printf("[sic] shutdown\n");
 173         moldyn_shutdown(&md);
 174
 175         return 0;
 176 }
 177