+ moldyn->vt2=0.0;
+ for(i=0;i<count;i++)
+ moldyn->vt2-=v3_scalar_product(&(itom[i].r),&(itom[i].f));
+
+printf("compare: vt1: %f vt2: %f\n",moldyn->vt1,moldyn->vt2);
+
+pressure_calc(moldyn);
+
+ return 0;
+}
+
+/*
+ * virial calculation
+ */
+
+inline int virial_calc(t_atom *a,t_3dvec *f,t_3dvec *d) {
+
+ a->virial.xx-=f->x*d->x;
+ a->virial.yy-=f->y*d->y;
+ a->virial.zz-=f->z*d->z;
+ a->virial.xy-=f->x*d->y;
+ a->virial.xz-=f->x*d->z;
+ a->virial.yz-=f->y*d->z;
+