+
+ /* prepare offset */
+ ox=0.0;
+ if(itom->r.x<0) {
+ while((itom->r.x+ox)<(-lac/2.0))
+ ox+=lac;
+ }
+ else {
+ while((itom->r.x+ox)>(lac/2.0))
+ ox-=lac;
+ }
+
+ oy=0.0;
+ if(itom->r.y<0) {
+ while((itom->r.y+oy)<(-lac/2.0))
+ oy+=lac;
+ }
+ else {
+ while((itom->r.y+oy)>(lac/2.0))
+ oy-=lac;
+ }
+
+ oz=0.0;
+ if(itom->r.z<0) {
+ while((itom->r.z+oz)<(-lac/2.0))
+ oz+=lac;
+ }
+ else {
+ while((itom->r.z+oz)>(lac/2.0))
+ oz-=lac;
+ }
+
+