Figure shows the characteristics of nucleation process when a groove of w = 16.32Å and d = 12.24Å is present on the substrate. Consistent with heterogeneous nucleation on flat surfaces, Figure (a) and (b) demonstrate that for strong interfacial interaction the bubble nucleates in the bulk while at reduced values of ε * nucleation is observed at the interface. Pressure-time plot for ε * = 0.5 shows the existence of two minimas, indicating that there exists two barriers to nucleation; this is discussed in the next Subsection. While reporting nucleation pressures, σ min , in Figure (c) we use the minimum σ min obtained in the pressure-time curves as overcoming both barriers are essential for nucleating a stable bubble. Variation of nucleation pressure with interfacial interaction shows similar behavior as compared to the cases when groove is absent (see Figure ). Unsurprisingly, for high values of ε * , the nucleation pressure is comparable to the bulk values whereas for low ε * , nucleation is easier when a groove is present.