Also allowed more CG steps in the tangent space when the EF step appears to have converged. Keyword 2D added.
System is treated as fixed in the x - y plane.
Not an efficient implementation, as derivatives for unwanted degrees of freedom are still calculated. The energy and derivatives add to the potential specified by the atom type. At low density some atoms may not interact with any others and problems result due to additional zero eigenvalues. There is a true minimum for their density with a cutoff of 1.25.