E

ΔE

NB

NS

ZE

PS

PB

NB

−1

−0.5

−0.5

0

0

Cluster 1

NS

−0.5

−0.5

−0.5

0

0.5

ZE

−0.5

−0.5

0

0.5

0.5

Cluster 2

PS

−0.5

0

0.5

0.5

1

PB

0

0

0.5

0.5

1

Cluster 3