Figure 3: Optimized displacement profile ⃗ δ i for screw dislocation on basal plane: edge component (open circles) and screw component (filled squares) are measured in units of the Burgers vector b = a = 3 . 63668 Å. Dashed lines indicate positions of partial dislocations. Table II: Core structure and Peierls Stress for four dislocations on the basal plane for the SWF model for solid hcp $^{4}$He . −40 −30 −20 −10 0 10 20 30 40 −0.2 −0.4 0.0 0.2 0.4 0.6 0.8 1.0 Atomic row Displacement ( b ) ISF Screw 30 ◦ 60 ◦ Edge Partial separation (Å) 91.3 109.1 119.7 127.3 Peierls Stress (MPa) $^{0.41}$±$^{0.01 0.015}$±$^{0.01 0.23}$±$^{0.01 0.08}$± 0 . 01 0 . 01 0 . 01 0 . 01 0 . 01 10