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 #include "posic.h"
  12
  13 /* potential */
  14 #include "potentials/harmonic_oscillator.h"
  15 #include "potentials/lennard_jones.h"
  16 #include "potentials/tersoff.h"
  17
  18 int hook(void *moldyn,void *hook_params) {
  19
  20         t_moldyn *md;
  21
  22         md=moldyn;
  23
  24         /* switch to direct scaling in first hook */
  25         if(md->schedule.count==0)
  26                 set_pt_scale(md,0,0,T_SCALE_BERENDSEN,100.0);
  27         /* switch off temp scaling in second hook */
  28         if(md->schedule.count==1)
  29                 set_pt_scale(md,0,0,0,0);
  30
  31         //set_temperature(md,md->t_ref-100.0);
  32
  33         return 0;
  34 }
  35
  36 int main(int argc,char **argv) {
  37
  38         /* check argv */
  39         if(argc!=3) {
  40                 printf("[sic] usage: %s <logdir> <temperatur>\n",argv[0]);
  41                 return -1;
  42         }
  43
  44         /* main moldyn structure */
  45         t_moldyn md;
  46
  47         /* potential parameters */
  48         t_lj_params lj;
  49         t_ho_params ho;
  50         t_tersoff_mult_params tp;
  51
  52         /* testing location & velocity vector */
  53         t_3dvec r,v;
  54         memset(&r,0,sizeof(t_3dvec));
  55         memset(&v,0,sizeof(t_3dvec));
  56
  57         /* initialize moldyn */
  58         moldyn_init(&md,argc,argv);
  59
  60         /* choose integration algorithm */
  61         set_int_alg(&md,MOLDYN_INTEGRATE_VERLET);
  62
  63         /* choose potential */
  64         set_potential1b(&md,tersoff_mult_1bp);
  65         set_potential2b(&md,tersoff_mult_2bp);
  66         set_potential2b_post(&md,tersoff_mult_post_2bp);
  67         set_potential3b(&md,tersoff_mult_3bp);
  68         //set_potential2b(&md,lennard_jones);
  69         //set_potential2b(&md,harmonic_oscillator);
  70         set_potential_params(&md,&tp);
  71         //set_potential_params(&md,&lj);
  72         //set_potential_params(&md,&ho);
  73
  74         /* cutoff radius */
  75         set_cutoff(&md,TM_S_SI);
  76         //set_cutoff(&md,LC_SI*sqrt(3.0));
  77         //set_cutoff(&md,2.0*LC_SI);
  78
  79         /*
  80          * potential parameters
  81          */
  82
  83         /* lennard jones */
  84         lj.sigma6=LJ_SIGMA_SI*LJ_SIGMA_SI*LJ_SIGMA_SI;
  85         lj.sigma6*=lj.sigma6;
  86         lj.sigma12=lj.sigma6*lj.sigma6;
  87         lj.epsilon4=4.0*LJ_EPSILON_SI;
  88         lj.uc=lj.epsilon4*(lj.sigma12/pow(md.cutoff,12.0)-lj.sigma6/pow(md.cutoff,6));
  89
  90         /* harmonic oscillator */
  91         ho.equilibrium_distance=0.25*sqrt(3.0)*LC_SI;
  92         //ho.equilibrium_distance=LC_SI;
  93         ho.spring_constant=LJ_EPSILON_SI;
  94
  95         /*
  96          * tersoff mult potential parameters for SiC
  97          */
  98         tp.S[0]=TM_S_SI;
  99         tp.R[0]=TM_R_SI;
 100         tp.A[0]=TM_A_SI;
 101         tp.B[0]=TM_B_SI;
 102         tp.lambda[0]=TM_LAMBDA_SI;
 103         tp.mu[0]=TM_MU_SI;
 104         tp.beta[0]=TM_BETA_SI;
 105         tp.n[0]=TM_N_SI;
 106         tp.c[0]=TM_C_SI;
 107         tp.d[0]=TM_D_SI;
 108         tp.h[0]=TM_H_SI;
 109
 110         tp.S[1]=TM_S_C;
 111         tp.R[1]=TM_R_C;
 112         tp.A[1]=TM_A_C;
 113         tp.B[1]=TM_B_C;
 114         tp.lambda[1]=TM_LAMBDA_C;
 115         tp.mu[1]=TM_MU_C;
 116         tp.beta[1]=TM_BETA_C;
 117         tp.n[1]=TM_N_C;
 118         tp.c[1]=TM_C_C;
 119         tp.d[1]=TM_D_C;
 120         tp.h[1]=TM_H_C;
 121
 122         tp.chi=TM_CHI_SIC;
 123
 124         tersoff_mult_complete_params(&tp);
 125
 126         /* set (initial) dimensions of simulation volume */
 127         set_dim(&md,6*LC_SI,6*LC_SI,6*LC_SI,TRUE);
 128
 129         /* set periodic boundary conditions in all directions */
 130         set_pbc(&md,TRUE,TRUE,TRUE);
 131
 132         /* create the lattice / place atoms */
 133         //create_lattice(&md,CUBIC,LC_SI,SI,M_SI,
 134         //create_lattice(&md,FCC,LC_SI,SI,M_SI,
 135         create_lattice(&md,DIAMOND,LC_SI,SI,M_SI,
 136                        ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 137         //               ATOM_ATTR_2BP|ATOM_ATTR_HB,
 138                        0,6,6,6);
 139         moldyn_bc_check(&md);
 140
 141         /* testing configuration */
 142         //r.x=0.27*sqrt(3.0)*LC_SI/2.0; v.x=0;
 143         //r.x=(TM_S_SI+TM_R_SI)/4.0;    v.x=0;
 144         //r.y=0;                v.y=0;
 145         //r.z=0;                v.z=0;
 146         //add_atom(&md,SI,M_SI,0,
 147         //           ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 148         //           ATOM_ATTR_2BP|ATOM_ATTR_HB,
 149         //           &r,&v);
 150         //r.x=-r.x;     v.x=-v.x;
 151         //r.y=0;                v.y=0;
 152         //r.z=0;                v.z=0;
 153         //add_atom(&md,SI,M_SI,0,
 154         //           ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 155         //           ATOM_ATTR_2BP|ATOM_ATTR_HB,
 156         //           &r,&v);
 157         //r.x=0;                v.x=0;
 158         //r.y=0;        v.y=0;
 159         //r.z=sin(M_PI*60.0/180.0)*(TM_S_SI+TM_R_SI)/4.0;       v.z=0;
 160         //add_atom(&md,SI,M_SI,0,
 161         //           ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 162         //           ATOM_ATTR_2BP|ATOM_ATTR_HB,
 163         //           &r,&v);
 164
 165         /* set temperature & pressure */
 166         set_temperature(&md,atof(argv[2])+273.0);
 167         set_pressure(&md,ATM);
 168
 169         /* set p/t scaling */
 170         //set_pt_scale(&md,P_SCALE_BERENDSEN,0.001,
 171         //                 T_SCALE_BERENDSEN,100.0);
 172         //set_pt_scale(&md,0,0,T_SCALE_DIRECT,1.0);
 173         //set_pt_scale(&md,P_SCALE_BERENDSEN,0.001,0,0);
 174
 175         /* initial thermal fluctuations of particles (in equilibrium) */
 176         thermal_init(&md,TRUE);
 177
 178         /* create the simulation schedule */
 179         moldyn_add_schedule(&md,10001,1.0);
 180         //moldyn_add_schedule(&md,501,1.0);
 181         //moldyn_add_schedule(&md,501,1.0);
 182
 183         /* schedule hook function */
 184         //moldyn_set_schedule_hook(&md,&hook,NULL);
 185
 186         /* activate logging */
 187         moldyn_set_log_dir(&md,argv[1]);
 188         moldyn_set_report(&md,"Frank Zirkelbach","Test 1");
 189         moldyn_set_log(&md,LOG_TOTAL_ENERGY,1);
 190         moldyn_set_log(&md,VISUAL_STEP,100);
 191         moldyn_set_log(&md,CREATE_REPORT,0);
 192
 193         /*
 194          * let's do the actual md algorithm now
 195          *
 196          * integration of newtons equations
 197          */
 198         moldyn_integrate(&md);
 199
 200         /* close */
 201         moldyn_shutdown(&md);
 202
 203         return 0;
 204 }
 205