Piecewise linearity in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>G</mml:mi><mml:mi>W</mml:mi></mml:mrow></mml:math>approximation for accurate quasiparticle energy predictions

We identify the deviation from the straight-line error (DSLE)---i.e., the spurious nonlinearity of the total energy as a function of fractional particle numb...