2 * tersoff.h - tersoff potential header file
4 * author: Frank Zirkelbach <frank.zirkelbach@physik.uni-augsburg.de>
11 #define TERSOFF_MAXN 16*27
13 /* tersoff exchange type */
14 typedef struct s_tersoff_echange {
20 t_3dvec dist_ik[TERSOFF_MAXN];
21 double d_ik2[TERSOFF_MAXN];
22 double d_ik[TERSOFF_MAXN];
24 double f_c_ik[TERSOFF_MAXN];
25 double df_c_ik[TERSOFF_MAXN];
27 double g[TERSOFF_MAXN];
28 double dg[TERSOFF_MAXN];
29 double cos_theta[TERSOFF_MAXN];
48 /* tersoff mult (2!) potential parameters */
49 typedef struct s_tersoff_mult_params {
50 double S[2]; /* tersoff cutoff radii */
51 double S2[2]; /* tersoff cutoff radii squared */
52 double R[2]; /* tersoff cutoff radii */
53 double Smixed; /* mixed S radius */
54 double S2mixed; /* mixed S radius squared */
55 double Rmixed; /* mixed R radius */
56 double A[2]; /* factor of tersoff attractive part */
57 double B[2]; /* factor of tersoff repulsive part */
58 double Amixed; /* mixed A factor */
59 double Bmixed; /* mixed B factor */
60 double lambda[2]; /* tersoff lambda */
61 double lambda_m; /* mixed lambda */
62 double mu[2]; /* tersoff mu */
63 double mu_m; /* mixed mu */
73 t_tersoff_exchange exchange; /* exchange between 2bp and 3bp calc */
74 } t_tersoff_mult_params;
76 /* function prototypes */
77 int tersoff_mult_set_params(t_moldyn *moldyn,int element1,int element2);
78 int tersoff_mult_1bp(t_moldyn *moldyn,t_atom *ai);
79 int tersoff_mult_2bp(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
80 int tersoff_mult_3bp_j1(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
81 int tersoff_mult_3bp_k1(t_moldyn *moldyn,
82 t_atom *ai,t_atom *aj,t_atom *ak,u8 bc);
83 int tersoff_mult_3bp_j2(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
84 int tersoff_mult_3bp_k2(t_moldyn *moldyn,
85 t_atom *ai,t_atom *aj,t_atom *ak,u8 bc);
86 int tersoff_mult_check_2b_bond(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc);
88 /* tersoff potential paramter defines */
91 #define TM_R_SI 2.7 /* A */
92 #define TM_S_SI 3.0 /* A */
93 #define TM_A_SI (1830.8*EV) /* NA */
94 #define TM_B_SI (471.18*EV) /* NA */
95 #define TM_LAMBDA_SI 2.4799 /* 1/A */
96 #define TM_MU_SI 1.7322 /* 1/A */
97 #define TM_BETA_SI 1.1000e-6
98 #define TM_N_SI 0.78734
99 #define TM_C_SI 1.0039e5
100 #define TM_D_SI 16.217
101 #define TM_H_SI -0.59825
104 #define TM_R_C 1.8 /* A */
105 #define TM_S_C 2.1 /* A */
106 #define TM_A_C (1393.6*EV) /* NA */
107 #define TM_B_C (346.7*EV) /* NA */
108 #define TM_LAMBDA_C 3.4879 /* 1/A */
109 #define TM_MU_C 2.2119 /* 1/A */
110 #define TM_BETA_C 1.5724e-7
111 #define TM_N_C 0.72751
112 #define TM_C_C 3.8049e4
114 #define TM_H_C -0.57058
116 // mixed: silicon carbide
117 #define TM_CHI_SIC 0.9776
118 #define TM_LC_SIC 4.32 /* A */