pele.potentials.ATLJ.ATLJ

class pele.potentials.ATLJ.ATLJ(eps=1.0, sig=1.0, Z=1.0)

Lennard Jones + three body Axilrod-Teller term

V = sum_ij VLJ_ij + sum_ijk Z * (1 + 3*cos(t1)*cos(t2)*cos(t3)) / (rij * rjk * rik)**3 )

where t1, t2, t3 are the internal angles of the triangle ijk

Z > 0 stabilizes linear vs. triangular geometries

Methods

NumericalDerivative(coords[, eps])	return the gradient calculated numerically
NumericalHessian(coords[, eps])	return the Hessian matrix of second derivatives computed numerically
getEnergy(coords)	return the energy at the given coordinates
getEnergyFortran(coords)
getEnergyGradient(coords)	return the energy and gradient at the given coordinates
getEnergyGradientFortran(coords)
getEnergyGradientHessian(coords)	return the energy, gradient, and Hessian at the given coordinates
getEnergyGradientNumerical(coords)
getEnergySlow(coords)
getGradient(coords)	return the gradient at the given coordinates
getHessian(coords)	return the hessian
test_potential(coords[, eps])	print some information testing whether the analytical gradients are correct

Attributes