Advanced features
Beyond the core move set and the standard analysis, PIMMS has a handful of features aimed at harder sampling problems and specialised workflows: ramping the temperature during a run, pinning part of the system in place, spreading the hot moves across CPU cores, and enhanced-sampling temperature excursions. Each has its own page, listed under Advanced Features in the sidebar and summarised below.
One feature is still experimental and requires EXPERIMENTAL_FEATURES : True
in the keyfile (the VMMC move); it is flagged clearly on the page where it appears.
Experimental features are not guaranteed to behave correctly in every configuration,
so leave the gate off unless you specifically need it (see Reference ensembles & other advanced controls).
At a glance
Feature |
Key keyword(s) |
What it is for |
|---|---|---|
|
Ramp the temperature during a run - simulated annealing (cooling) to drive assembly, or heating to melt a structure. |
|
|
Hold chosen chains rigidly fixed as a scaffold, surface or template that the mobile chains still interact with. |
|
|
Run the crankshaft, slither and pull moves on multi-threaded “checkerboard” kernels for large systems. |
|
|
Temperature-excursion (tempered-transitions) moves that help the system hop over energy barriers ordinary moves cannot cross. |
|
|
Run your own Python analysis code against the live lattice during the run. |
|
|
Reference ensembles, energy-consistency checks, box/trajectory controls and the experimental gate. |
None of these features change what PIMMS is sampling unless you ask them to: a
freeze file and PARALLELIZE leave the target Boltzmann distribution untouched,
a quench deliberately changes the temperature along a schedule you specify, and the
TSMMC moves are constructed to preserve detailed balance. Where a feature does
alter the physics (a quench, or NON_INTERACTING) that is the whole point of it,
and the page says so explicitly.