Read Appendix A and establish formulae (1.4.15) and (1.4.16). Estimate the importance of the linear term in these formulae, relative to the main term \((\pi / 6) \varepsilon^{* 3 / 2}\), for an oxygen molecule confined to a cube of side \(10 \mathrm{~cm}\); take \(\varepsilon=0.05 \mathrm{eV}\).