Observation and resonant x-ray optical interpretation of multi-atom resonant photoemission effects in O<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>1</mml:mn><mml:mi>s</mml:mi></mml:mrow></mml:math>emission from NiO
Physical review. B, Condensed matter and materials physics