Body-force shear (Couette-like): apply F_x = m·γ̇·(y−y_c) to every atom, so each layer gets a uniform shear rate γ̇. Top atoms drift in +x, bottom in −x. No frozen boundaries, no surface artifacts; the deformation is uniform shear by construction.

For a solid: at small γ̇ the shear strain γ accumulates linearly in time (γ(t) = γ̇·t) until the elastic restoring force balances the body force. Steady-state strain: γ_∞ = γ̇·m·D / k_eff (where k_eff is effective elastic stiffness).

URL params: ?shear=1e-5&n=5.

γ̇ (1/au-time²)  n Apply & rerun

Status: setting up…
Shear rate γ̇: — 1/au-time²
y_center: — grid cells
Total atoms: —

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Top-atom v_x (live): — au/t
Bottom-atom v_x (live): — au/t
Top-atom δ_x (live): — au
Bottom-atom δ_x (live): — au
Strain γ = (δ_top−δ_bot)/L_y (live): —

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Accumulated shear work _shearWork: — Ha

Watch: δ_x(top) growing positive, δ_x(bottom) growing negative; γ should plateau at steady state. Then γ_∞/γ̇ relates to elastic stiffness.
Reference: NaCl C₄₄ ≈ 12.6 GPa.