A model for calculating the uniaxial pressure derivatives of the critical temperature in Hg-12 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.svg"> <mml:mrow> <mml:mrow> <mml:mo stretchy="true">(</mml:mo> <mml:mrow> <mml:mi>n</mml:mi> <mml:mo linebreak="badbreak">−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> <mml:mo stretchy="true">)</mml:mo> </mml:mrow> <mml:mi>n</mml:mi> </mml:mrow> </mml:math> superconductors: A Casimir energy scenario