Please run with -tao_monitor -tao_converged_reason and see why it has stopped.
Barry > On Jun 26, 2024, at 4:34 PM, Palmer, Bruce J via petsc-users > <petsc-users@mcs.anl.gov> wrote: > > This Message Is From an External Sender > This message came from outside your organization. > Hi, > > I’m trying to do an unconstrained optimization on a molecular scale problem. > Previously, I was looking at an artificial molecular problem where all > parameters were of order 1 and so the objective function and variables were > also in the range of 1 or at least within a few orders of magnitude of 1. > > More recently, I’ve been trying to apply this optimization to a real > molecular system. Between Avogadro’s number (6.022e23) and Boltzmann’s > constant (1.38e-16) combined with very small distances (1.0e-8 cm), etc. the > objective function values and the values of the optimization variables have > very large values (~1e86 and ~1e9, respectively). I’ve verified that the > analytic gradients of the objective function that I’m calculating are correct > by comparing them with numerical derivatives. > > I’ve tried using the LMVM and Conjugate Gradient optimizations, both of which > worked previously, but I find that the optimization completes one objective > function evaluation and then declares that the problem is converged and > stops. I could find a set of units where everything is approximately 1 but I > was hoping that there are some parameters I can set in the optimization that > will get it moving again. Any suggestions? > > Bruce Palmer
