 Termination status: 4
 Line search fails, too many secant steps
 Possible causes of this error message:
   - your tolerance (grad_tol = 0.1000D-07) may be too strict
 absolute largest component of gradient: 0.2923D-06
 function value:  -6.5307867273306169E+02
 cg iterations: 28
 function evaluations: 146
 gradient evaluations: 132
