Gradient

equation (2.12)
(2.12)

Example

potentialfunction
Gaussianexp[-r2]
Coloumb1/r
Dipole1/r - 1/r
Tight bindingcos(x)+cos(y)
Saddle pointx2-y2

* r = (x2+y2)1/2

3D viewer

Rotation:
drag a point pressing the left button.
Close up:
drag a point pressing the left button with [Shift] key on the keyboard.
function:
2D view
3D view
3D visualization by Three.js (MIT License)

return