2 * sic.c - investigation of the sic precipitation process of silicon carbide
4 * author: Frank Zirkelbach <frank.zirkelbach@physik.uni-augsburg.de>
14 int hook(void *moldyn,void *hook_params) {
20 /* decrease temperature in every hook */
21 set_temperature(md,md->t_ref-100.0);
26 int main(int argc,char **argv) {
30 printf("[sic] usage: %s <logdir> <temperatur>\n",argv[0]);
34 /* main moldyn structure */
37 /* potential parameters */
40 t_tersoff_mult_params tp;
42 /* testing location & velocity vector */
45 /* initialize moldyn */
46 moldyn_init(&md,argc,argv);
48 /* choose integration algorithm */
49 set_int_alg(&md,MOLDYN_INTEGRATE_VERLET);
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);
60 //set_cutoff(&md,TM_S_SI);
61 set_cutoff(&md,2*LC_SI);
64 * potential parameters
68 lj.sigma6=LJ_SIGMA_SI*LJ_SIGMA_SI*LJ_SIGMA_SI;
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));
74 /* harmonic oscillator */
75 ho.equilibrium_distance=0.25*sqrt(3.0)*LC_SI;
76 ho.spring_constant=.1;
79 * tersoff mult potential parameters for SiC
85 tp.lambda[0]=TM_LAMBDA_SI;
87 tp.beta[0]=TM_BETA_SI;
97 tp.lambda[1]=TM_LAMBDA_C;
107 tersoff_mult_complete_params(&tp);
109 /* set (initial) dimensions of simulation volume */
110 set_dim(&md,6*LC_SI,6*LC_SI,6*LC_SI,TRUE);
112 /* set periodic boundary conditions in all directions */
113 set_pbc(&md,TRUE,TRUE,TRUE);
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,
120 moldyn_bc_check(&md);
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;
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,
131 //r.x=-r.x; v.x=-v.x;
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,
139 /* setting a nearest neighbour distance for the moldyn checks */
140 set_nn_dist(&md,0.25*sqrt(3.0)*LC_SI); /* diamond ! */
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);
151 set_pressure(&md,ATM);
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);
159 /* initial thermal fluctuations of particles (in equilibrium) */
160 thermal_init(&md,TRUE);
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);
172 /* schedule hook function */
173 moldyn_set_schedule_hook(&md,&hook,NULL);
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);
181 * let's do the actual md algorithm now
183 * integration of newtons equations
185 moldyn_integrate(&md);
188 moldyn_shutdown(&md);