Flexible MOF Generation with Torsion-Aware Flow Matching

TL;DR

This paper introduces a two-stage generative framework for MOFs that models both chemical and geometric features, enabling the creation of novel, valid, and diverse frameworks with complex 3D structures.

Contribution

It presents a novel two-stage approach combining SMILES-based generation and flow matching for flexible MOF design, overcoming previous limitations.

Findings

Improved reconstruction accuracy of MOFs.

Generation of valid, novel, and diverse MOFs.

Ability to create new building blocks for MOFs.

Abstract

Designing metal-organic frameworks (MOFs) with novel chemistries is a longstanding challenge due to their large combinatorial space and complex 3D arrangements of the building blocks. While recent deep generative models have enabled scalable MOF generation, they assume (1) a fixed set of building blocks and (2) known local 3D coordinates of building blocks. However, this limits their ability to (1) design novel MOFs and (2) generate the structure using novel building blocks. We propose a two-stage MOF generation framework that overcomes these limitations by modeling both chemical and geometric degrees of freedom. First, we train an SMILES-based autoregressive model to generate metal and organic building blocks, paired with a cheminformatics toolkit for 3D structure initialization. Second, we introduce a flow matching model that predicts translations, rotations, and torsional angles to assemble the blocks into valid 3D frameworks. Our experiments demonstrate improved reconstruction accuracy, the generation of valid, novel, and unique MOFs, and the ability to create novel building blocks. Our code is available at https://github.com/nayoung10/MOFFlow-2.