2 electrons in a 1-d box

y1(x1)y1(x2)

Y*Y

y1(x1)y2(x2)

 Y*Y

y2(x1)y1(x2)

 Y*Y

0.7071*[y1(x1)y2(x2)-y2(x1)y1(x2)]

 Y*Y

0.7071*[y1(x1)y2(x2)+y2(x1)y1(x2)]

 Y*Y