X-Git-Url: https://www.hackdaworld.org/gitweb/?a=blobdiff_plain;f=potentials%2Ftersoff.c;h=6bfcf30e0239ce2d0fa964607ff2ef9098ce403d;hb=92ef07d77a4c879527180224acea73a3f6564497;hp=531d292131121ad5acb7b1ce2a4a0c551199b34a;hpb=0b96eb313c9bfec6272b1f8de0d99c4ce26d1686;p=physik%2Fposic.git

diff --git a/potentials/tersoff.c b/potentials/tersoff.c
index 531d292..6bfcf30 100644
--- a/potentials/tersoff.c
+++ b/potentials/tersoff.c
@@ -94,6 +94,9 @@ int tersoff_mult_2bp(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
 	double s_r;
 	double arg;
 
+	printf("WARNING! - tersoff_mult_2bp is obsolete.\n");
+	printf("WARNING! - repulsive part handled in 3bp/j2 routine.\n");
+
 	/* use newtons third law */
 	if(ai<aj) return 0;
 
@@ -153,7 +156,7 @@ int tersoff_mult_2bp(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
 
 	/* add forces */
 	v3_add(&(ai->f),&(ai->f),&force);
-	v3_sub(&(aj->f),&(aj->f),&force);
+	v3_sub(&(aj->f),&(aj->f),&force); // reason: dri rij = - drj rij
 
 #ifdef DEBUG
 	if((ai==&(moldyn->atom[0]))|(aj==&(moldyn->atom[0]))) {
@@ -167,14 +170,7 @@ int tersoff_mult_2bp(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
 #endif
 
 	/* virial */
-	//virial_calc(ai,&force,&dist_ij);
-	//virial_calc(aj,&force,&dist_ij);
-	//ai->virial.xx-=force.x*dist_ij.x;
-	//ai->virial.yy-=force.y*dist_ij.y;
-	//ai->virial.zz-=force.z*dist_ij.z;
-	//ai->virial.xy-=force.x*dist_ij.y;
-	//ai->virial.xz-=force.x*dist_ij.z;
-	//ai->virial.yz-=force.y*dist_ij.z;
+	virial_calc(ai,&force,&dist_ij);
 
 	/* energy 2bp contribution */
 	moldyn->energy+=f_r*f_c;
@@ -316,6 +312,14 @@ int tersoff_mult_3bp_k1(t_moldyn *moldyn,
 		exchange->zeta_ij+=f_c_ik*g;
 	}
 
+#ifdef DEBUG
+	if((ai==&(moldyn->atom[0]))|
+	   (aj==&(moldyn->atom[864]))|
+	   (ak==&(moldyn->atom[1003]))) {
+		printf(" -> %f %f %f\n",exchange->ci2di2,frac,h_cos);
+	}
+#endif
+
 	/* store even more data for second k loop */
 	exchange->g[kcount]=g;
 	exchange->dg[kcount]=dg;
@@ -336,7 +340,10 @@ int tersoff_mult_3bp_j2(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
 	t_tersoff_exchange *exchange;
 	t_3dvec force;
 	double f_a,df_a,b,db,f_c,df_c;
+	double f_r,df_r;
+	double scale;
 	double mu,B,chi;
+	double lambda,A;
 	double d_ij;
 	unsigned char brand;
 	double ni,tmp;
@@ -350,14 +357,18 @@ int tersoff_mult_3bp_j2(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
 		S=params->S[brand];
 		R=params->R[brand];
 		B=params->B[brand];
+		A=params->A[brand];
 		mu=params->mu[brand];
+		lambda=params->lambda[brand];
 		chi=1.0;
 	}
 	else {
 		S=params->Smixed;
 		R=params->Rmixed;
 		B=params->Bmixed;
+		A=params->Amixed;
 		mu=params->mu_m;
+		lambda=params->lambda_m;
 		chi=params->chi;
 	}
 
@@ -379,6 +390,10 @@ int tersoff_mult_3bp_j2(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
 	f_a=-B*exp(-mu*d_ij);
 	df_a=mu*f_a/d_ij;
 
+	/* f_r, df_r */
+	f_r=A*exp(-lambda*d_ij);
+	df_r=lambda*f_r/d_ij;
+
 	/* b, db */
 	if(exchange->zeta_ij==0.0) {
 		b=chi;
@@ -388,16 +403,16 @@ int tersoff_mult_3bp_j2(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
 		ni=*(exchange->n_i);
 		tmp=exchange->betaini*pow(exchange->zeta_ij,ni-1.0);
 		b=(1.0+exchange->zeta_ij*tmp);
-		db=chi*pow(b,-1.0/(2*ni)-1.0);
+		db=chi*pow(b,-1.0/(2.0*ni)-1.0);
 		b=db*b;
 		db*=-0.5*tmp;
 	}
 
 	/* force contribution */
-	v3_scale(&force,&(exchange->dist_ij),df_a*f_c+f_a*df_c);
-	v3_scale(&force,&force,-0.5*b);
+	scale=-0.5*(f_c*(df_r+b*df_a)+df_c*(f_r+b*df_a));
+	v3_scale(&force,&(exchange->dist_ij),scale);
 	v3_add(&(ai->f),&(ai->f),&force);
-	v3_sub(&(aj->f),&(aj->f),&force);
+	v3_sub(&(aj->f),&(aj->f),&force); // dri rij = - drj rij
 
 #ifdef DEBUG
 	if((ai==&(moldyn->atom[0]))|(aj==&(moldyn->atom[0]))) {
@@ -407,18 +422,21 @@ int tersoff_mult_3bp_j2(t_moldyn *moldyn,t_atom *ai,t_atom *aj,u8 bc) {
 			printf("total i: %f %f %f\n",ai->f.x,ai->f.y,ai->f.z);
 		if(aj==&(moldyn->atom[0]))
 			printf("total j: %f %f %f\n",aj->f.x,aj->f.y,aj->f.z);
+		printf("energy: %f = %f %f %f %f\n",0.5*f_c*(b*f_a+f_r),
+		                                    f_c,b,f_a,f_r);
+		printf("        %f %f %f\n",exchange->zeta_ij,.0,.0);
 	}
 #endif
 
 	/* virial */
-	//virial_calc(ai,&force,&(exchange->dist_ij));
-	//virial_calc(aj,&force,&(exchange->dist_ij));
+	if(aj<ai)
+		virial_calc(ai,&force,&(exchange->dist_ij));
 
 	/* dzeta prefactor = - 0.5 f_c f_a db */
 	exchange->pre_dzeta=-0.5*f_a*f_c*db;
 
 	/* energy contribution */
-	moldyn->energy+=0.5*f_c*b*f_a;
+	moldyn->energy+=0.5*f_c*(b*f_a+f_r);
 
 	/* reset k counter for second k loop */
 	exchange->kcount=0;
@@ -522,7 +540,7 @@ int tersoff_mult_3bp_k2(t_moldyn *moldyn,
 	/* virial */
 	//virial_calc(ai,&force,&dist_ij);
 
-	/* derivatice wrt j */
+	/* derivative wrt j */
 	v3_scale(&force,&dcosdrj,fcdg*pre_dzeta);
 
 	/* force contribution */
@@ -537,10 +555,12 @@ int tersoff_mult_3bp_k2(t_moldyn *moldyn,
 #endif
 
 	/* virial */
-	//virial_calc(aj,&force,&dist_ij);
+	//v3_scale(&force,&force,-1.0);
+	if(aj<ai)
+		virial_calc(ai,&force,&dist_ij);
 
 	/* derivative wrt k */
-	v3_scale(&force,&dist_ik,dfcg);
+	v3_scale(&force,&dist_ik,-1.0*dfcg); // dri rik = - drk rik
 	v3_scale(&tmp,&dcosdrk,fcdg);
 	v3_add(&force,&force,&tmp);
 	v3_scale(&force,&force,pre_dzeta);
@@ -557,7 +577,9 @@ int tersoff_mult_3bp_k2(t_moldyn *moldyn,
 #endif
 
 	/* virial */
-	virial_calc(ak,&force,&dist_ik);
+	//v3_scale(&force,&force,-1.0);
+	if(aj<ai)
+		virial_calc(ai,&force,&dist_ik);
 	
 	/* increase k counter */
 	exchange->kcount++;