Re: HOW IS THE STRUCTURE OF Cu-Cl DRAWN UP?

HOW IS THE STRUCTURE OF Cu-Cl DRAWN UP?

WE WERE SHOWN A DIAGRAM OF Cu-Cl--IN THE FORM OF A CUBE--AND WERE BEING TAUGHT ABOUT ITS STRUCTURE. MANY COMPOUNDS ARE UNIFORM AND EASY TO UNDERSTAND WHEN YOU LOOK AT THEM, HOWEVER, THE PROFESSOR WAS UNSURE WHY THIS PARTICULAR STRUCTURE DIDN'T HAVE COPPER ATOMS--I HOPE I'M EXPLAINING THIS CLEARLY--IN "EACH" OF THE NINE SUB-DIVIDED CUBES. THERE WERE ONE-EIGHTH CHLORINE ATOMS ON EACH OF THE CORNERS, AND ONE-HALF CHLORINE ATOMS ON THE FACES OF THE CUBE--WHICH SEEMED NORMAL. BUT, ENTIRE COPPER ATOMS SORT OF ALTERNATED THROUGHOUT THE CUBE. ADDING UP THE CHARGES OF THE ATOMS, I FOUND THAT IT WAS SEEMED LIKE A VALID DIAGRAM WHEN BALANCING THE CHARGES AND RATIOS--STILL, WHY IS IT THAT THE COPPER IONS WERE PLACED THAT WAY?
PROFESSOR AND ALL, WE'RE ALL STUMPED. THINK YOU CAN HELP ME?

You may have something in which eight of these cubes are fused face-to-face into a single "supercube", in which case you would have the following:

• eight copper atoms, one in the center of each of the eight cubes;
• eight 1/8 chlorines (one in each corner of the "supercube");
• eight 1/4 chlorines (one in the middle of each edge of the "supercube");
• eight 1/2 chlorines (one in the center of each face of the "supercube");
• one whole chlorine (in the very center of the "supercube").

It may be that you are looking at the diagram incorrectly, which is easy to do with an extended crystal structure diagram! Often, too, the perspectives are a bit weird which doesn't make it any easier. Or perhaps the atoms in edges and corners are shown whole?

If this doesn't help, please feel free to contact me.