2 * moldyn.h - molecular dynamics library header file
4 * author: Frank Zirkelbach <frank.zirkelbach@physik.uni-augsburg.de>
11 #include "math/math.h"
12 #include "random/random.h"
13 #include "list/list.h"
22 typedef unsigned char u8;
25 typedef struct s_virial {
26 double xx; /* | xx xy xz | */
27 double yy; /* V = | yx yy yz | */
28 double zz; /* | zx zy zz | */
30 double xz; /* with: xy=yx, xz=zx, yz=zy */
34 /* the atom of the md simulation */
35 typedef struct s_atom {
36 t_3dvec r; /* position */
37 t_3dvec v; /* velocity */
38 t_3dvec f; /* force */
39 t_virial virial; /* virial */
40 double e; /* site energy */
41 int element; /* number of element in pse */
42 double mass; /* atom mass */
43 u8 brand; /* brand id */
44 int tag; /* atom unique id (number of atom) */
45 u8 attr; /* attributes */
48 #define ATOM_ATTR_FP 0x01 /* fixed position (bulk material) */
49 #define ATOM_ATTR_HB 0x02 /* coupled to heat bath (velocity scaling) */
51 #define ATOM_ATTR_1BP 0x10 /* single paricle potential */
52 #define ATOM_ATTR_2BP 0x20 /* pair potential */
53 #define ATOM_ATTR_3BP 0x40 /* 3 body potential */
56 typedef struct s_linkcell {
57 int nx,ny,nz; /* amount of cells in x, y and z direction */
58 int cells; /* total amount of cells */
59 double len; /* prefered cell edge length */
60 double x,y,z; /* the actual cell lengthes */
61 t_list *subcell; /* pointer to the cell lists */
62 int dnlc; /* direct neighbour lists counter */
65 #include "visual/visual.h"
67 /* moldyn schedule structure */
68 typedef struct s_moldyn_schedule {
73 int (*hook)(void *moldyn,void *hook_params);
77 /* moldyn main structure */
78 typedef struct s_moldyn {
79 int count; /* total amount of atoms */
80 t_atom *atom; /* pointer to the atoms */
82 t_3dvec dim; /* dimensions of the simulation volume */
83 double volume; /* volume of sim cell (dim.x*dim.y*dim.z) */
85 /* potential force function and parameter pointers */
86 int (*func1b)(struct s_moldyn *moldyn,t_atom *ai);
87 int (*func2b)(struct s_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
88 int (*func3b_j1)(struct s_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
89 int (*func3b_j2)(struct s_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
90 int (*func3b_j3)(struct s_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
91 int (*func3b_k1)(struct s_moldyn *moldyn,
92 t_atom *ai,t_atom *aj,t_atom *ak,u8 bck);
93 int (*func3b_k2)(struct s_moldyn *moldyn,
94 t_atom *ai,t_atom *aj,t_atom *ak,u8 bck);
98 double cutoff; /* cutoff radius */
99 double cutoff_square; /* square of the cutoff radius */
100 double nnd; /* nearest neighbour distance (optional) */
102 t_linkcell lc; /* linked cell list interface */
104 double t_ref; /* reference temperature */
105 double t; /* actual temperature */
106 double t_sum; /* sum over all t */
107 double mean_t; /* mean value of t */
109 t_virial virial; /* global virial (absolute coordinates) */
110 double gp; /* pressure computed from global virial */
111 double gp_sum; /* sum over all gp */
112 double mean_gp; /* mean value of gp */
114 double p_ref; /* reference pressure */
115 double p; /* actual pressure (computed by virial) */
116 double p_sum; /* sum over all p */
117 double mean_p; /* mean value of p */
118 t_3dvec tp; /* thermodynamic pressure dU/dV */
119 double dv; /* dV for thermodynamic pressure calc */
121 /* pressure and temperature control (velocity/volume scaling) */
122 /* (t_tc in units of tau, p_tc in units of tau * isoth. compressib.) */
123 unsigned char pt_scale; /* type of p and t scaling */
124 double t_tc; /* t berendsen control time constant */
125 double p_tc; /* p berendsen control time constant */
127 /* simulation schedule */
128 t_moldyn_schedule schedule;
129 int current; /* current position in schedule */
131 /* integration function pointer */
132 int (*integrate)(struct s_moldyn *moldyn);
133 int time_steps; /* amount of iterations */
134 double tau; /* delta t */
135 double time; /* absolute time */
136 double tau_square; /* delta t squared */
137 int total_steps; /* total steps */
139 double energy; /* potential energy */
140 double ekin; /* kinetic energy */
142 char vlsdir[128]; /* visualization/log/save directory */
143 t_visual vis; /* visualization interface structure */
144 u8 vlsprop; /* log/vis/save properties */
145 unsigned int ewrite; /* how often to log energy */
146 int efd; /* fd for energy log */
147 unsigned int mwrite; /* how often to log momentum */
148 int mfd; /* fd for momentum log */
149 unsigned int pwrite; /* how often to log pressure */
150 int pfd; /* fd for pressure log */
151 unsigned int twrite; /* how often to log temperature */
152 int tfd; /* fd for temperature log */
153 unsigned int vwrite; /* how often to visualize atom information */
154 unsigned int swrite; /* how often to create a save file */
155 int rfd; /* report file descriptor */
156 char rtitle[64]; /* report title */
157 char rauthor[64]; /* report author */
158 int epfd; /* energy gnuplot script file descriptor */
159 int ppfd; /* pressure gnuplot script file descriptor */
160 int tpfd; /* temperature gnuplot script file descriptor */
162 u8 status; /* general moldyn properties */
164 t_random random; /* random interface */
166 double debug; /* debugging stuff, ignore */
175 #define MOLDYN_STAT_PBX 0x01 /* periodic boudaries in x */
176 #define MOLDYN_STAT_PBY 0x02 /* y */
177 #define MOLDYN_STAT_PBZ 0x04 /* and z direction */
179 #define MOLDYN_PSCALE 0x08 /* size controlled by piston */
181 #define MOLDYN_1BP 0x10 /* care about single */
182 #define MOLDYN_2BP 0x20 /* 2 body */
183 #define MOLDYN_3BP 0x40 /* and 3 body particle pots */
185 #define T_SCALE_BERENDSEN 0x01 /* berendsen t control */
186 #define T_SCALE_DIRECT 0x02 /* direct t control */
187 #define P_SCALE_BERENDSEN 0x04 /* berendsen p control */
188 #define P_SCALE_DIRECT 0x08 /* direct p control */
191 * default values & units
193 * - length unit: 1 A (1 A = 1e-10 m)
194 * - time unit: 1 fs (1 fs = 1e-15 s)
195 * - mass unit: 1 amu (1 amu = 1.6605388628e-27 kg )
197 * fyi: in the following 1 N = (amu*A)/(fs*fs)
201 #define METER 1e10 /* A */
202 #define SECOND 1e15 /* fs */
203 #define AMU 1.6605388628e-27 /* kg */
204 #define KILOGRAM (1.0/AMU) /* amu */
205 #define NEWTON (METER*KILOGRAM/(SECOND*SECOND)) /* A amu / fs^2 */
206 #define PASCAL (NEWTON/(METER*METER)) /* N / A^2 */
207 #define BAR ((1.0e5*PASCAL)) /* N / A^2 */
208 #define K_BOLTZMANN (1.380650524e-23*METER*NEWTON) /* NA/K */
209 #define EV (1.6021765314e-19*METER*NEWTON) /* NA */
211 #define MOLDYN_TEMP 273.0
212 #define MOLDYN_TAU 1.0
213 #define MOLDYN_CUTOFF 10.0
214 #define MOLDYN_RUNS 1000000
216 #define MOLDYN_INTEGRATE_VERLET 0x00
217 #define MOLDYN_INTEGRATE_DEFAULT MOLDYN_INTEGRATE_VERLET
219 #define MOLDYN_POTENTIAL_HO 0x00
220 #define MOLDYN_POTENTIAL_LJ 0x01
221 #define MOLDYN_POTENTIAL_TM 0x02
223 #define LOG_TOTAL_ENERGY 0x01
224 #define LOG_TOTAL_MOMENTUM 0x02
225 #define LOG_PRESSURE 0x04
226 #define LOG_TEMPERATURE 0x08
227 #define SAVE_STEP 0x10
228 #define VISUAL_STEP 0x20
229 #define CREATE_REPORT 0x40
238 * potential related phsical values / constants
242 #define ONE_THIRD (1.0/3.0)
245 #define M_C 12.011 /* amu */
248 #define LC_SI (0.543105e-9*METER) /* A */
249 #define M_SI 28.08553 /* amu */
251 #define LJ_SIGMA_SI ((0.25*sqrt(3.0)*LC_SI)/1.122462) /* A */
252 //#define LJ_SIGMA_SI (LC_SI/1.122462) /* A */
253 //#define LJ_SIGMA_SI (0.5*sqrt(2.0)*LC_SI/1.122462) /* A */
254 #define LJ_EPSILON_SI (2.1678*EV) /* NA */
256 #define TM_R_SI (2.7e-10*METER) /* A */
257 #define TM_S_SI (3.0e-10*METER) /* A */
258 #define TM_A_SI (1830.8*EV) /* NA */
259 #define TM_B_SI (471.18*EV) /* NA */
260 #define TM_LAMBDA_SI (2.4799e10/METER) /* 1/A */
261 #define TM_MU_SI (1.7322e10/METER) /* 1/A */
262 #define TM_BETA_SI 1.1000e-6
263 #define TM_N_SI 0.78734
264 #define TM_C_SI 1.0039e5
265 #define TM_D_SI 16.217
266 #define TM_H_SI -0.59825
268 #define TM_R_C (1.8e-10*METER) /* A */
269 #define TM_S_C (2.1e-10*METER) /* A */
270 #define TM_A_C (1393.6*EV) /* NA */
271 #define TM_B_C (346.7*EV) /* NA */
272 #define TM_LAMBDA_C (3.4879e10/METER) /* 1/A */
273 #define TM_MU_C (2.2119e10/METER) /* 1/A */
274 #define TM_BETA_C 1.5724e-7
275 #define TM_N_C 0.72751
276 #define TM_C_C 3.8049e4
278 #define TM_H_C -0.57058
280 #define TM_CHI_SIC 0.9776
293 * function prototypes
297 typedef int (*pf_func1b)(t_moldyn *,t_atom *);
298 typedef int (*pf_func2b)(t_moldyn *,t_atom *,t_atom *,u8);
299 typedef int (*pf_func3b)(t_moldyn *,t_atom *,t_atom *,t_atom *,u8);
301 int moldyn_init(t_moldyn *moldyn,int argc,char **argv);
302 int moldyn_shutdown(t_moldyn *moldyn);
304 int set_int_alg(t_moldyn *moldyn,u8 algo);
305 int set_cutoff(t_moldyn *moldyn,double cutoff);
306 int set_temperature(t_moldyn *moldyn,double t_ref);
307 int set_pressure(t_moldyn *moldyn,double p_ref);
308 int set_pt_scale(t_moldyn *moldyn,u8 ptype,double ptc,u8 ttype,double ttc);
309 int set_dim(t_moldyn *moldyn,double x,double y,double z,u8 visualize);
310 int set_nn_dist(t_moldyn *moldyn,double dist);
311 int set_pbc(t_moldyn *moldyn,u8 x,u8 y,u8 z);
312 int set_potential1b(t_moldyn *moldyn,pf_func1b func);
313 int set_potential2b(t_moldyn *moldyn,pf_func2b func);
314 int set_potential3b_j1(t_moldyn *moldyn,pf_func2b func);
315 int set_potential3b_j2(t_moldyn *moldyn,pf_func2b func);
316 int set_potential3b_j3(t_moldyn *moldyn,pf_func2b func);
317 int set_potential3b_k1(t_moldyn *moldyn,pf_func3b func);
318 int set_potential3b_k2(t_moldyn *moldyn,pf_func3b func);
319 int set_potential_params(t_moldyn *moldyn,void *params);
321 int moldyn_set_log_dir(t_moldyn *moldyn,char *dir);
322 int moldyn_set_report(t_moldyn *moldyn,char *author,char *title);
323 int moldyn_set_log(t_moldyn *moldyn,u8 type,int timer);
324 int moldyn_log_shutdown(t_moldyn *moldyn);
326 int create_lattice(t_moldyn *moldyn,u8 type,double lc,int element,double mass,
327 u8 attr,u8 brand,int a,int b,int c);
328 int cubic_init(int a,int b,int c,double lc,t_atom *atom,t_3dvec *origin);
329 int fcc_init(int a,int b,int c,double lc,t_atom *atom,t_3dvec *origin);
330 int diamond_init(int a,int b,int c,double lc,t_atom *atom,t_3dvec *origin);
331 int add_atom(t_moldyn *moldyn,int element,double mass,u8 brand,u8 attr,
332 t_3dvec *r,t_3dvec *v);
333 int destroy_atoms(t_moldyn *moldyn);
335 int thermal_init(t_moldyn *moldyn,u8 equi_init);
336 double temperature_calc(t_moldyn *moldyn);
337 double get_temperature(t_moldyn *moldyn);
338 int scale_velocity(t_moldyn *moldyn,u8 equi_init);
339 double pressure_calc(t_moldyn *moldyn);
340 double thermodynamic_pressure_calc(t_moldyn *moldyn);
341 double get_pressure(t_moldyn *moldyn);
342 int scale_volume(t_moldyn *moldyn);
343 int scale_dim(t_moldyn *moldyn,double scale,u8 x,u8 y,u8 z);
344 int scale_atoms(t_moldyn *moldyn,double scale,u8 x,u8 y,u8 z);
346 double e_kin_calc(t_moldyn *moldyn);
347 double get_total_energy(t_moldyn *moldyn);
348 t_3dvec get_total_p(t_moldyn *moldyn);
350 double estimate_time_step(t_moldyn *moldyn,double nn_dist);
352 int link_cell_init(t_moldyn *moldyn,u8 vol);
353 int link_cell_update(t_moldyn *moldyn);
354 int link_cell_neighbour_index(t_moldyn *moldyn,int i,int j,int k,t_list *cell);
355 int link_cell_shutdown(t_moldyn *moldyn);
357 typedef int (*set_hook)(void *,void *);
359 int moldyn_add_schedule(t_moldyn *moldyn,int runs,double tau);
360 int moldyn_set_schedule_hook(t_moldyn *moldyn,set_hook hook,void *hook_params);
362 int moldyn_integrate(t_moldyn *moldyn);
363 int velocity_verlet(t_moldyn *moldyn);
365 int potential_force_calc(t_moldyn *moldyn);
366 int virial_calc(t_atom *a,t_3dvec *f,t_3dvec *d);
367 //inline int virial_calc(t_atom *a,t_3dvec *f,t_3dvec *d)
368 // __attribute__((always_inline));
369 int check_per_bound(t_moldyn *moldyn,t_3dvec *a);
370 //inline int check_per_bound(t_moldyn *moldyn,t_3dvec *a)
371 // __attribute__((always_inline));
373 int moldyn_bc_check(t_moldyn *moldyn);