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