Add symplectic integrator#43
Open
johannes-spies wants to merge 10 commits into
Open
Conversation
Pass model=(flashmd_model, (symplectic_model, config_dict)) to use the fixed-point midpoint-rule integrator instead of plain FlashMD. The plain single-model API is completely unchanged. Works in both i-PI and ASE (VelocityVerlet, Bussi, Langevin). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This was referenced May 19, 2026
The `._nl.algorithm = "cell_list"` workaround guards against a vesin CUDA bug with triclinic cells (vesin#157), but accesses a private attribute. It was not present in the original PR#32 design, and verified to be unnecessary on CPU (the only target for now). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
…per" This reverts commit 7c1aa52.
frostedoyster
left a comment
frostedoyster
left a comment
Collaborator
There was a problem hiding this comment.
Looks good. Can we also support (direct_model, symplectic_model) without the symplectic config? It should be trivial. We also need tests. For that, we will need to upload the symplectic models to the HF repository. We also need some documentation
Allow passing the symplectic model directly as the second tuple element, without wrapping it in a (model, config) pair. Defaults to empty config. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
VelocityVerlet assumed the symplectic model was always passed as (model, config); passing just a plain model crashed with TypeError. Also adds pytest filterwarnings for torch.jit and metatomic 0.1.12+ deprecations (renamed output names/quantities) that now surface with newer dependency versions. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Extend get_pretrained() with symplectic=True to download and export the symplectic FlashMD checkpoint from HuggingFace. Add tests covering both the plain-model and (model, config) tuple API. Metatrain is pinned to the git HEAD for now since experimental.flashmd_symplectic is not yet in a released version. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Pin metatrain to 2026.2.1 in pyproject.toml. In get_pretrained, check the mtt export return code and give a helpful error if the experimental.flashmd_symplectic architecture is missing. Override metatrain with a pinned metatensor/metatrain commit in CI so the symplectic tests can actually run the export. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
warp-lang>=1.14.0 deprecated warp.config.quiet, which is used by nvalchemi-toolkit-ops==0.3.0. Suppress it so pytest's filterwarnings error mode doesn't turn it into a failure. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
The existing filter only matched APICLaunchParamRecord; warp-lang 1.14.0 triggers the same warning for other ctypes structures (e.g. APICLaunchPtrLocation) on Python 3.14. Use .* to suppress all of them. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Adds a fixed-point midpoint-rule symplectic integrator with minimal changes to the existing API.
src/flashmd/fpi.py: Anderson-accelerated fixed-point solver (ported from Add Symplectic Integrator #32).src/flashmd/symplectic_stepper.py:SymplecticStepper— wraps aFlashMDStepperfor the initial guess and refines it using a separate symplectic correction model.ipi.pyandase/velocity_verlet.py: tuple model detection. The plain single-model API is completely unchanged.Usage
Pass a tuple instead of a plain model wherever a model is expected:
The
configdict keys are all optional and passed straight toanderson_solver:tol,max_iter,m,beta,lambda_reg.This supersedes #32, which is being closed in favour of this smaller focused change. The example will follow in a separate PR on top of this one.