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
  55         /* initialize moldyn */
  56         moldyn_init(&md,argc,argv);
  57
  58         /* choose integration algorithm */
  59         set_int_alg(&md,MOLDYN_INTEGRATE_VERLET);
  60
  61         /* choose potential */
  62         //set_potential1b(&md,tersoff_mult_1bp,&tp);
  63         //set_potential2b(&md,tersoff_mult_2bp,&tp);
  64         //set_potential2b_post(&md,tersoff_mult_post_2bp,&tp);
  65         //set_potential3b(&md,tersoff_mult_3bp,&tp);
  66         set_potential2b(&md,lennard_jones,&lj);
  67         //set_potential2b(&md,harmonic_oscillator,&ho);
  68
  69         /* cutoff radius */
  70         //set_cutoff(&md,TM_S_SI);
  71         //set_cutoff(&md,2*LC_SI*0.5*sqrt(1.5));
  72         set_cutoff(&md,2.0*LC_SI);
  73
  74         /*
  75          * potential parameters
  76          */
  77
  78         /* lennard jones */
  79         lj.sigma6=LJ_SIGMA_SI*LJ_SIGMA_SI*LJ_SIGMA_SI;
  80         lj.sigma6*=lj.sigma6;
  81         lj.sigma12=lj.sigma6*lj.sigma6;
  82         lj.epsilon4=4.0*LJ_EPSILON_SI;
  83         lj.uc=lj.epsilon4*(lj.sigma12/pow(md.cutoff,12.0)-lj.sigma6/pow(md.cutoff,6));
  84
  85         /* harmonic oscillator */
  86         //ho.equilibrium_distance=0.25*sqrt(3.0)*LC_SI;
  87         ho.equilibrium_distance=LC_SI;
  88         ho.spring_constant=LJ_EPSILON_SI;
  89
  90         /*
  91          * tersoff mult potential parameters for SiC
  92          */
  93         tp.S[0]=TM_S_SI;
  94         tp.R[0]=TM_R_SI;
  95         tp.A[0]=TM_A_SI;
  96         tp.B[0]=TM_B_SI;
  97         tp.lambda[0]=TM_LAMBDA_SI;
  98         tp.mu[0]=TM_MU_SI;
  99         tp.beta[0]=TM_BETA_SI;
 100         tp.n[0]=TM_N_SI;
 101         tp.c[0]=TM_C_SI;
 102         tp.d[0]=TM_D_SI;
 103         tp.h[0]=TM_H_SI;
 104
 105         tp.S[1]=TM_S_C;
 106         tp.R[1]=TM_R_C;
 107         tp.A[1]=TM_A_C;
 108         tp.B[1]=TM_B_C;
 109         tp.lambda[1]=TM_LAMBDA_C;
 110         tp.mu[1]=TM_MU_C;
 111         tp.beta[1]=TM_BETA_C;
 112         tp.n[1]=TM_N_C;
 113         tp.c[1]=TM_C_C;
 114         tp.d[1]=TM_D_C;
 115         tp.h[1]=TM_H_C;
 116
 117         tp.chi=TM_CHI_SIC;
 118
 119         tersoff_mult_complete_params(&tp);
 120
 121         /* set (initial) dimensions of simulation volume */
 122         set_dim(&md,6*LC_SI,6*LC_SI,6*LC_SI,TRUE);
 123
 124         /* set periodic boundary conditions in all directions */
 125         set_pbc(&md,TRUE,TRUE,TRUE);
 126
 127         /* create the lattice / place atoms */
 128         //create_lattice(&md,CUBIC,LC_SI,SI,M_SI,
 129         create_lattice(&md,FCC,LC_SI,SI,M_SI,
 130         //create_lattice(&md,DIAMOND,LC_SI,SI,M_SI,
 131         //               ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 132                        ATOM_ATTR_2BP|ATOM_ATTR_HB,
 133                        0,6,6,6);
 134         moldyn_bc_check(&md);
 135
 136         /* testing configuration */
 137         //r.x=0.28*sqrt(3)*LC_SI/2;     v.x=0;
 138         //r.x=1.75*LC_SI;       v.x=-0.01;
 139         //r.y=0;                v.y=0;
 140         //r.z=0;                v.z=0;
 141         //add_atom(&md,SI,M_SI,0,
 142         //           ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 143         //           ATOM_ATTR_2BP|ATOM_ATTR_HB,
 144         //           &r,&v);
 145         //r.x=-r.x;     v.x=-v.x;
 146         //r.y=0;                v.y=0;
 147         //r.z=0;                v.z=0;
 148         //add_atom(&md,SI,M_SI,0,
 149         //           ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 150         //           ATOM_ATTR_2BP|ATOM_ATTR_HB,
 151         //           &r,&v);
 152
 153         /* set temperature & pressure */
 154         set_temperature(&md,atof(argv[2])+273.0);
 155         set_pressure(&md,ATM);
 156
 157         /* set p/t scaling */
 158         //set_pt_scale(&md,P_SCALE_BERENDSEN,0.001,
 159         //                 T_SCALE_BERENDSEN,100.0);
 160         //set_pt_scale(&md,0,0,T_SCALE_DIRECT,1.0);
 161         //set_pt_scale(&md,P_SCALE_BERENDSEN,0.001,0,0);
 162
 163         /* initial thermal fluctuations of particles (in equilibrium) */
 164         thermal_init(&md,TRUE);
 165
 166         /* create the simulation schedule */
 167         moldyn_add_schedule(&md,101,1.0);
 168         //moldyn_add_schedule(&md,501,1.0);
 169         //moldyn_add_schedule(&md,501,1.0);
 170
 171         /* schedule hook function */
 172         //moldyn_set_schedule_hook(&md,&hook,NULL);
 173
 174         /* activate logging */
 175         moldyn_set_log_dir(&md,argv[1]);
 176         moldyn_set_report(&md,"Frank Zirkelbach","Test 1");
 177         moldyn_set_log(&md,LOG_TOTAL_ENERGY,1);
 178         moldyn_set_log(&md,VISUAL_STEP,1);
 179         moldyn_set_log(&md,CREATE_REPORT,0);
 180
 181         /*
 182          * let's do the actual md algorithm now
 183          *
 184          * integration of newtons equations
 185          */
 186         moldyn_integrate(&md);
 187
 188         /* close */
 189         moldyn_shutdown(&md);
 190
 191         return 0;
 192 }
 193