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 "math/math.h"
  12 #include "init/init.h"
  13 #include "visual/visual.h"
  14
  15 #include "posic.h"
  16
  17 int main(int argc,char **argv) {
  18         /* main moldyn structure */
  19         t_moldyn md;
  20
  21         /* potential parameters */
  22         t_lj_params lj;
  23         t_ho_params ho;
  24         t_tersoff_mult_params tp;
  25
  26         /* misc parameters */
  27         double tau;
  28
  29         /* testing location & velocity vector */
  30         t_3dvec r,v;
  31
  32         /* values */
  33         tau=1.0e-15;    /* delta t = 1 fs */
  34
  35         /* initialize moldyn */
  36         printf("[sic] moldyn init\n");
  37         moldyn_init(&md,argc,argv);
  38
  39         /* choose integration algorithm */
  40         printf("[sic] setting integration algorithm\n");
  41         set_int_alg(&md,MOLDYN_INTEGRATE_VERLET);
  42
  43         /* choose potential */
  44         printf("[sic] selecting potential\n");
  45         set_potential1b(&md,tersoff_mult_1bp,&tp);
  46         set_potential2b(&md,tersoff_mult_2bp,&tp);
  47         set_potential2b_post(&md,tersoff_mult_post_2bp,&tp);
  48         set_potential3b(&md,tersoff_mult_3bp,&tp);
  49         //set_potential2b(&md,lennard_jones,&lj);
  50
  51         /*
  52          * potential parameters
  53          */
  54
  55         /* lennard jones */
  56         lj.sigma6=LJ_SIGMA_SI*LJ_SIGMA_SI*LJ_SIGMA_SI;
  57         lj.sigma6*=lj.sigma6;
  58         lj.sigma12=lj.sigma6*lj.sigma6;
  59         lj.epsilon4=4.0*LJ_EPSILON_SI;
  60
  61         /* harmonic oscillator */
  62         ho.equilibrium_distance=0.25*sqrt(3.0)*LC_SI;
  63         ho.spring_constant=1;
  64
  65         /*
  66          * tersoff mult potential parameters for SiC
  67          */
  68         tp.S[0]=TM_S_SI;
  69         tp.R[0]=TM_R_SI;
  70         tp.A[0]=TM_A_SI;
  71         tp.B[0]=TM_B_SI;
  72         tp.lambda[0]=TM_LAMBDA_SI;
  73         tp.mu[0]=TM_MU_SI;
  74         tp.beta[0]=TM_BETA_SI;
  75         tp.n[0]=TM_N_SI;
  76         tp.c[0]=TM_C_SI;
  77         tp.d[0]=TM_D_SI;
  78         tp.h[0]=TM_H_SI;
  79
  80         tp.S[1]=TM_S_C;
  81         tp.R[1]=TM_R_C;
  82         tp.A[1]=TM_A_C;
  83         tp.B[1]=TM_B_C;
  84         tp.lambda[1]=TM_LAMBDA_C;
  85         tp.mu[1]=TM_MU_C;
  86         tp.beta[1]=TM_BETA_C;
  87         tp.n[1]=TM_N_C;
  88         tp.c[1]=TM_C_C;
  89         tp.d[1]=TM_D_C;
  90         tp.h[1]=TM_H_C;
  91
  92         tp.chi=TM_CHI_SIC;
  93
  94         tersoff_mult_complete_params(&tp);
  95
  96         /* cutoff radius */
  97         printf("[sic] setting cutoff radius\n");
  98         set_cutoff(&md,TM_S_SI);
  99         //set_cutoff(&md,2*LC_SI);
 100
 101         /* set (initial) dimensions of simulation volume */
 102         printf("[sic] setting dimensions\n");
 103         set_dim(&md,5*LC_SI,5*LC_SI,5*LC_SI,TRUE);
 104
 105         /* set periodic boundary conditions in all directions */
 106         printf("[sic] setting periodic boundary conditions\n");
 107         set_pbc(&md,TRUE,TRUE,TRUE);
 108
 109         /* create the lattice / place atoms */
 110         printf("[sic] creating atoms\n");
 111         //create_lattice(&md,DIAMOND,LC_SI,SI,M_SI,
 112          //              ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,
 113           //             //ATOM_ATTR_2BP|ATOM_ATTR_HB,
 114            //            0,5,5,5);
 115
 116         /* testing configuration */
 117         r.x=-0.55*0.25*sqrt(3.0)*LC_SI; v.x=0;
 118         r.y=0;                  v.y=0;
 119         r.z=0;                  v.z=0;
 120         add_atom(&md,SI,M_SI,0,ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,&r,&v);
 121         r.x=+0.55*0.25*sqrt(3.0)*LC_SI; v.x=0;
 122         r.y=0;                  v.y=0;
 123         r.z=0;                  v.z=0;
 124         add_atom(&md,SI,M_SI,0,ATOM_ATTR_1BP|ATOM_ATTR_2BP|ATOM_ATTR_3BP|ATOM_ATTR_HB,&r,&v);
 125
 126         /* setting a nearest neighbour distance for the moldyn checks */
 127         set_nn_dist(&md,0.25*sqrt(3.0)*LC_SI); /* diamond ! */
 128
 129         /* set temperature */
 130         printf("[sic] setting temperature\n");
 131         //set_temperature(&md,273.0+450.0);
 132         set_temperature(&md,0.0);
 133
 134         /* set p/t scaling */
 135         printf("[sic] set p/t scaling\n");
 136         set_pt_scale(&md,0,0,T_SCALE_BERENDSEN,100*tau);
 137
 138         /* initial thermal fluctuations of particles (in equilibrium) */
 139         printf("[sic] thermal init\n");
 140         thermal_init(&md,TRUE);
 141
 142         /* create the simulation schedule */
 143         printf("[sic] adding schedule\n");
 144         moldyn_add_schedule(&md,1000,1.0e-15);
 145
 146         /* activate logging */
 147         printf("[sic] activate logging\n");
 148         moldyn_set_log(&md,LOG_TOTAL_ENERGY,"saves/test-energy",10);
 149         moldyn_set_log(&md,VISUAL_STEP,"saves/test-visual",10);
 150
 151         /*
 152          * let's do the actual md algorithm now
 153          *
 154          * integration of newtons equations
 155          */
 156
 157         printf("[sic] integration start, go get a coffee ...\n");
 158         moldyn_integrate(&md);
 159
 160         /* close */
 161
 162         printf("[sic] shutdown\n");
 163         moldyn_shutdown(&md);
 164
 165         return 0;
 166 }
 167