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"
23 typedef unsigned char u8;
26 typedef struct s_virial {
27 double xx; /* | xx xy xz | */
28 double yy; /* V = | yx yy yz | */
29 double zz; /* | zx zy zz | */
31 double xz; /* with: xy=yx, xz=zx, yz=zy */
35 /* the atom of the md simulation */
36 typedef struct s_atom {
37 t_3dvec r; /* position */
38 t_3dvec v; /* velocity */
39 t_3dvec f; /* force */
40 t_virial virial; /* virial */
41 double e; /* site energy */
42 int element; /* number of element in pse */
43 double mass; /* atom mass */
44 u8 brand; /* brand id */
45 int tag; /* atom unique id (number of atom) */
46 u8 attr; /* attributes */
49 #define ATOM_ATTR_FP 0x01 /* fixed position (bulk material) */
50 #define ATOM_ATTR_HB 0x02 /* coupled to heat bath (velocity scaling) */
52 #define ATOM_ATTR_1BP 0x10 /* single paricle potential */
53 #define ATOM_ATTR_2BP 0x20 /* pair potential */
54 #define ATOM_ATTR_3BP 0x40 /* 3 body potential */
57 typedef struct s_linkcell {
58 int nx,ny,nz; /* amount of cells in x, y and z direction */
59 int cells; /* total amount of cells */
60 double len; /* prefered cell edge length */
61 double x,y,z; /* the actual cell lengthes */
62 t_list *subcell; /* pointer to the cell lists */
63 int dnlc; /* direct neighbour lists counter */
66 #include "visual/visual.h"
68 /* moldyn schedule structure */
69 typedef struct s_moldyn_schedule {
74 int (*hook)(void *moldyn,void *hook_params);
78 /* moldyn main structure */
79 typedef struct s_moldyn {
80 int count; /* total amount of atoms */
81 t_atom *atom; /* pointer to the atoms */
83 t_3dvec dim; /* dimensions of the simulation volume */
84 double volume; /* volume of sim cell (dim.x*dim.y*dim.z) */
87 /* potential force function and parameter pointers */
88 int (*func1b)(struct s_moldyn *moldyn,t_atom *ai);
90 int (*func2b)(struct s_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
91 int (*func2b_post)(struct s_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
93 int (*func3b)(struct s_moldyn *moldyn,t_atom *ai,t_atom *aj,t_atom *ak,
96 //int (*potential_force_function)(struct s_moldyn *moldyn);
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 */
107 double p_ref; /* reference pressure */
108 double p; /* actual pressure */
110 /* pressure and temperature control (velocity/volume scaling) */
111 /* (t_tc in units of tau, p_tc in units of tau * isoth. compressib.) */
112 unsigned char pt_scale; /* type of p and t scaling */
113 double t_tc; /* t berendsen control time constant */
114 double p_tc; /* p berendsen control time constant */
116 /* simulation schedule */
117 t_moldyn_schedule schedule;
118 int current; /* current position in schedule */
120 /* integration function pointer */
121 int (*integrate)(struct s_moldyn *moldyn);
122 int time_steps; /* amount of iterations */
123 double tau; /* delta t */
124 double time; /* absolute time */
125 double tau_square; /* delta t squared */
126 double elapsed; /* total elapsed time */
128 double energy; /* potential energy */
129 double ekin; /* kinetic energy */
131 char vlsdir[128]; /* visualization/log/save directory */
132 t_visual vis; /* visualization interface structure */
133 u8 vlsprop; /* log/vis/save properties */
134 unsigned int ewrite; /* how often to log energy */
135 int efd; /* fd for energy log */
136 unsigned int mwrite; /* how often to log momentum */
137 int mfd; /* fd for momentum log */
138 unsigned int vwrite; /* how often to visualize atom information */
139 unsigned int swrite; /* how often to create a save file */
141 u8 status; /* general moldyn properties */
143 t_random random; /* random interface */
145 int debug; /* debugging stuff, ignore */
148 #define MOLDYN_STAT_PBX 0x01 /* periodic boudaries in x */
149 #define MOLDYN_STAT_PBY 0x02 /* y */
150 #define MOLDYN_STAT_PBZ 0x04 /* and z direction */
152 #define MOLDYN_PSCALE 0x08 /* size controlled by piston */
154 #define MOLDYN_1BP 0x10 /* care about single */
155 #define MOLDYN_2BP 0x20 /* 2 body */
156 #define MOLDYN_3BP 0x40 /* and 3 body particle pots */
158 #define T_SCALE_BERENDSEN 0x01 /* berendsen t control */
159 #define T_SCALE_DIRECT 0x02 /* direct t control */
160 #define P_SCALE_BERENDSEN 0x04 /* berendsen p control */
161 #define P_SCALE_DIRECT 0x08 /* direct p control */
166 * potential parameter structures
171 * harmonic oscillator potential parameter structure
174 typedef struct s_ho_params {
175 double spring_constant;
176 double equilibrium_distance;
180 * lennard jones potential parameter structure
183 typedef struct s_lj_params {
194 /* tersoff exchange structure to exchange 2bp and 3bp calculated values */
195 typedef struct s_tersoff_exchange {
233 } t_tersoff_exchange;
235 /* tersoff multi (2!) potential parameters */
236 typedef struct s_tersoff_mult_params {
237 double S[2]; /* tersoff cutoff radii */
238 double S2[2]; /* tersoff cutoff radii squared */
239 double R[2]; /* tersoff cutoff radii */
240 double Smixed; /* mixed S radius */
241 double S2mixed; /* mixed S radius squared */
242 double Rmixed; /* mixed R radius */
243 double A[2]; /* factor of tersoff attractive part */
244 double B[2]; /* factor of tersoff repulsive part */
245 double Amixed; /* mixed A factor */
246 double Bmixed; /* mixed B factor */
247 double lambda[2]; /* tersoff lambda */
248 double lambda_m; /* mixed lambda */
249 double mu[2]; /* tersoff mu */
250 double mu_m; /* mixed mu */
260 t_tersoff_exchange exchange; /* exchange between 2bp and 3bp calc */
261 } t_tersoff_mult_params;
271 #define ONE_THIRD (1.0/3.0)
276 * - length unit: 1 A (1 A = 1e-10 m)
277 * - time unit: 1 fs (1 fs = 1e-15 s)
278 * - mass unit: 1 amu (1 amu = 1.6605388628e-27 kg )
280 * fyi: in the following 1 N = (amu*A)/(fs*fs)
284 #define METER 1e10 /* A */
285 #define SECOND 1e15 /* fs */
286 #define AMU 1.6605388628e-27 /* kg */
287 #define KILOGRAM (1.0/AMU) /* amu */
288 #define NEWTON (METER*KILOGRAM/(SECOND*SECOND)) /* A amu / fs^2 */
289 #define PASCAL (NEWTON/(METER*METER)) /* N / A^2 */
290 #define ATM (1.0133e5*PASCAL) /* N / A^2 */
292 #define MOLDYN_TEMP 273.0
293 #define MOLDYN_TAU 1.0
294 #define MOLDYN_CUTOFF 10.0
295 #define MOLDYN_RUNS 1000000
297 #define MOLDYN_INTEGRATE_VERLET 0x00
298 #define MOLDYN_INTEGRATE_DEFAULT MOLDYN_INTEGRATE_VERLET
300 #define MOLDYN_POTENTIAL_HO 0x00
301 #define MOLDYN_POTENTIAL_LJ 0x01
302 #define MOLDYN_POTENTIAL_TM 0x02
304 #define LOG_TOTAL_ENERGY 0x01
305 #define LOG_TOTAL_MOMENTUM 0x02
306 #define SAVE_STEP 0x04
307 #define VISUAL_STEP 0x08
314 * phsical values / constants
319 #define K_BOLTZMANN (1.380650524e-23*METER*NEWTON) /* NA/K */
320 #define EV (1.6021765314e-19*METER*NEWTON) /* NA */
323 #define M_C 12.011 /* amu */
326 #define LC_SI (0.543105e-9*METER) /* A */
327 #define M_SI 28.08553 /* amu */
329 #define LJ_SIGMA_SI ((0.25*sqrt(3.0)*LC_SI)/1.122462) /* A */
330 #define LJ_EPSILON_SI (2.1678*EV) /* NA */
332 #define TM_R_SI (2.7e-10*METER) /* A */
333 #define TM_S_SI (3.0e-10*METER) /* A */
334 #define TM_A_SI (1830.8*EV) /* NA */
335 #define TM_B_SI (471.18*EV) /* NA */
336 #define TM_LAMBDA_SI (2.4799e10/METER) /* 1/A */
337 #define TM_MU_SI (1.7322e10/METER) /* 1/A */
338 #define TM_BETA_SI 1.1000e-6
339 #define TM_N_SI 0.78734
340 #define TM_C_SI 1.0039e5
341 #define TM_D_SI 16.217
342 #define TM_H_SI -0.59825
344 #define TM_R_C (1.8e-10*METER) /* A */
345 #define TM_S_C (2.1e-10*METER) /* A */
346 #define TM_A_C (1393.6*EV) /* NA */
347 #define TM_B_C (346.7*EV) /* NA */
348 #define TM_LAMBDA_C (3.4879e10/METER) /* 1/A */
349 #define TM_MU_C (2.2119e10/METER) /* 1/A */
350 #define TM_BETA_C 1.5724e-7
351 #define TM_N_C 0.72751
352 #define TM_C_C 3.8049e4
354 #define TM_H_C -0.57058
356 #define TM_CHI_SIC 0.9776
368 * function prototypes
372 typedef int (*pf_func1b)(t_moldyn *,t_atom *ai);
373 typedef int (*pf_func2b)(t_moldyn *,t_atom *,t_atom *,u8 bc);
374 typedef int (*pf_func2b_post)(t_moldyn *,t_atom *,t_atom *,u8 bc);
375 typedef int (*pf_func3b)(t_moldyn *,t_atom *,t_atom *,t_atom *,u8 bc);
377 int moldyn_init(t_moldyn *moldyn,int argc,char **argv);
378 int moldyn_shutdown(t_moldyn *moldyn);
380 int set_int_alg(t_moldyn *moldyn,u8 algo);
381 int set_cutoff(t_moldyn *moldyn,double cutoff);
382 int set_temperature(t_moldyn *moldyn,double t_ref);
383 int set_pressure(t_moldyn *moldyn,double p_ref);
384 int set_pt_scale(t_moldyn *moldyn,u8 ptype,double ptc,u8 ttype,double ttc);
385 int set_dim(t_moldyn *moldyn,double x,double y,double z,u8 visualize);
386 int set_nn_dist(t_moldyn *moldyn,double dist);
387 int set_pbc(t_moldyn *moldyn,u8 x,u8 y,u8 z);
388 int set_potential1b(t_moldyn *moldyn,pf_func1b func,void *params);
389 int set_potential2b(t_moldyn *moldyn,pf_func2b func,void *params);
390 int set_potential2b_post(t_moldyn *moldyn,pf_func2b_post func,void *params);
391 int set_potential3b(t_moldyn *moldyn,pf_func3b func,void *params);
393 int moldyn_set_log_dir(t_moldyn *moldyn,char *dir);
394 int moldyn_set_log(t_moldyn *moldyn,u8 type,int timer);
395 int moldyn_log_shutdown(t_moldyn *moldyn);
397 int create_lattice(t_moldyn *moldyn,u8 type,double lc,int element,double mass,
398 u8 attr,u8 brand,int a,int b,int c);
399 int fcc_init(int a,int b,int c,double lc,t_atom *atom,t_3dvec *origin);
400 int diamond_init(int a,int b,int c,double lc,t_atom *atom,t_3dvec *origin);
401 int add_atom(t_moldyn *moldyn,int element,double mass,u8 brand,u8 attr,
402 t_3dvec *r,t_3dvec *v);
403 int destroy_atoms(t_moldyn *moldyn);
405 int thermal_init(t_moldyn *moldyn,u8 equi_init);
406 double temperature_calc(t_moldyn *moldyn);
407 double get_temperature(t_moldyn *moldyn);
408 int scale_velocity(t_moldyn *moldyn,u8 equi_init);
409 double pressure_calc(t_moldyn *moldyn);
410 double get_pressure(t_moldyn *moldyn);
411 int scale_volume(t_moldyn *moldyn);
413 double get_e_kin(t_moldyn *moldyn);
414 double update_e_kin(t_moldyn *moldyn);
415 double get_total_energy(t_moldyn *moldyn);
416 t_3dvec get_total_p(t_moldyn *moldyn);
418 double estimate_time_step(t_moldyn *moldyn,double nn_dist);
420 int link_cell_init(t_moldyn *moldyn);
421 int link_cell_update(t_moldyn *moldyn);
422 int link_cell_neighbour_index(t_moldyn *moldyn,int i,int j,int k,t_list *cell);
423 int link_cell_shutdown(t_moldyn *moldyn);
425 typedef int (*set_hook)(void *,void *);
427 int moldyn_add_schedule(t_moldyn *moldyn,int runs,double tau);
428 int moldyn_set_schedule_hook(t_moldyn *moldyn,set_hook hook,void *hook_params);
430 int moldyn_integrate(t_moldyn *moldyn);
431 int velocity_verlet(t_moldyn *moldyn);
433 int potential_force_calc(t_moldyn *moldyn);
434 inline int virial_calc(t_atom *a,t_3dvec *f,t_3dvec *d)
435 __attribute__((always_inline));
436 inline int check_per_bound(t_moldyn *moldyn,t_3dvec *a)
437 __attribute__((always_inline));
438 int harmonic_oscillator(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
439 int lennard_jones(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
440 int tersoff_mult_complete_params(t_tersoff_mult_params *p);
441 int tersoff_mult_1bp(t_moldyn *moldyn,t_atom *ai);
442 int tersoff_mult_2bp(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
443 int tersoff_mult_post_2bp(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
444 int tersoff_mult_3bp(t_moldyn *moldyn,t_atom *ai,t_atom *aj,t_atom *ak,u8 bc);
446 int moldyn_bc_check(t_moldyn *moldyn);