Invariance of the J and K operators

How does the Coulombic operator change upon a unitary transformation of the spinorbitals Let us see. 

1 Just as three fingers held at right angles do not cease to be of the same length (normalization) after rotation of your palm and continue to be orthogonal. 

Electronic Motion in the Mean Field Atoms and Molecules 

The operator /(.I) proves to be identical with the operator J(l). Similarly we may prove the invariance of the operator K. 

The operators J and K are invariant with respect to any unitary transformation of the spinorbitals. 

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